From rfrench@cs.stanford.edu Tue Feb  9 12:12:14 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA13952; Tue, 9 Feb 93 01:11:02 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA14873; Mon, 8 Feb 93 22:11:04 -0800
Date: Mon, 8 Feb 93 22:11:04 -0800
Message-Id: <9302090611.AA14873@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: Larry London <london@sunsite.unc.edu>
In-Reply-To: Larry London's message of Tue, 9 Feb 1993 00:28:04 -0500 (EST)
	<Pine.2.4.53.9302090009.F13090@calypso>
Subject: Re: Subscription to Hydroponics mailing list.
Status: RO
X-Status: 

Welcome to the hydroponics mailing list!

Submissions to the list should be sent to:

		hydro@hawg.stanford.edu

Messages to this address will automatically be broadcast to all list
members.

Requests to be added to or deleted from the list should be sent to:

		hydro-request@hawg.stanford.edu

We have people from all over the country on this list.  It appears
that most are beginners when it comes to hydroponic gardening, so
personal experiences will probably be interesting to everyone.

			Happy Gardening!

From rfrench@cs.stanford.edu Tue Feb  9 12:13:08 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA14042; Tue, 9 Feb 93 01:14:41 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA14881; Mon, 8 Feb 93 22:13:38 -0800
Date: Mon, 8 Feb 93 22:13:38 -0800
Message-Id: <9302090613.AA14881@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Archives
Status: RO
X-Status: 


I will make an archive of all relevant messages sent to this list
available for anonymous ftp (unless there are objections...) so that
latecomers can see the information.  You can retrieve it from the file
pub/hydro/archive on hawg.stanford.edu.

			Rob

From rfrench@cs.stanford.edu Sun Feb 14 01:05:50 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA05467; Sun, 14 Feb 93 00:35:32 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA02198; Sat, 13 Feb 93 21:33:25 -0800
Date: Sat, 13 Feb 93 21:33:25 -0800
Message-Id: <9302140533.AA02198@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Hydroponics books
Status: RO
X-Status: 


Ok, we've now reached 20 list members and zero messages, so I thought
I'd start something.  (Many of the people on this list have indicated
that they're total beginners at this, so please don't be shy about
asking questions.  I'm sure the info will be useful to everyone.)

I've used the following two books for all my hydroponics information
so far.  Does anyone have any suggestions for other good books?

Richard E. Nicholls, "Beginning Hydroponics: Soilless Gardening",
Running Press Books.  I found this an excellent introduction.

Raymond Bridwell, "Hydroponic Gardening", Woodbridge Press.  This is
touted as the "number 1 book" but I found it very hard to extract
specific information from; he has a rambling conversational style that
I find somewhat annoying.




From london@sunsite.unc.edu Sun Feb 14 12:16:30 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA06327; Sun, 14 Feb 93 01:41:59 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA02262; Sat, 13 Feb 93 22:39:42 -0800
Received: by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA06308; Sun, 14 Feb 93 01:39:32 EST
Date: Sun, 14 Feb 1993 01:39:32 -0500 (EST)
From: Larry London <london@sunsite.unc.edu>
Subject: Hydroponics - publications & general info
To: hydro@Hawg.Stanford.EDU
Message-Id: <Pine.2.4.53.9302140104.A6278@calypso>
Status: O
X-Status: 



(from Usenet, rec.gardens & misc.rural newsgroups):

--*--
I'd like to recommend a magazine which I have found most helpful regarding
growlights, hydroponics, and gardening in general.

Its called "The Growing Edge" and has been around for a few years now,
publishing quarterly.  The byline reads "Indoor and Outdoor Gardening for
Today's High-Tech Grower" and the magazine is just that.  For example, here's
a list of the articles in the Summer '91 issue:

   Thigmomorphogenesis - Plant Abuse as a Cultivation Technique
   Surfless and Turfless - A New Wave of Integrated Food Production
   Bioponics Part IV
   Good Vibrations - A 'Sound Diet' for Plants
   Drip Irrigation - The Basics
   New Efficiency for Home Lighting

And there are a number of regular columns, one of which reports on recent
scientific studies and what was discovered.  Lots of good info on hydroponic
methods as well.  The magazine is thin and costly ($5 an issue) but quite
informative.  You might check your local university library, or you can call
directly for a sample issue ($6.50 first class mail) 1-800-888-6785.  Several
of the garden shops in Seattle sell the magazine, as does one newstand.  It
appears to be quite popular.

Actually, I don't have a subscription yet myself, as there is a local library
that has it.  The back issues are particularly informative.  One other source
of good information has been manufacturers catalogs.  They often contain
charts comparing light emission, talk about growing methods, contain advice,
etc.  If you are interested in growing under lights or growing hydroponically
you may want to call and ask for some catalogs.  Here are some numbers:

     Diamond Lights:  1-800-331-3994
     General Hydroponics:  1-800-486-6001
     Worm's Way:  1-800-274-9676
     Light Manufacturing Co:  1-800-669-5483

--*--
Subject: Hydroponic gardening source
A few weeks (?) ago someone was asking for info on hydroponic gardening.
Today I came across the following:
        Hydrofarm Gardening Products
        3135 Kerner Boulevard
        San Rafael, CA  94901

as an address to mail to for their free catalog (lights, hydroponic
supplies, books, videos, etc.).  I've never grown hydroponically
nor have I ever dealt with this company, but I thought whoever was
interested might wish to write them.

--*--
>Does anyone out there have knowledge of a good source of information for
>hydroponics?  This would include product reviews of commercial kits, recipes
>for nutrient solutions, instructions for DIY set ups.  Thanks in advance.

I don't know where to get reviews of commercial kits.  Recipes for
solutions can be found in a number of places, including Wyman's
Gardening Encyclopedia, and in a book in the list below.  I'm told,
however, that unless you plan a large hydroponic garden, or just like
to experiment, it is not worth it to mix your own nutrients.

I have this book: "Beginning Hydroponics: Soilless Gardening" Richard
E. Nicholls, Running Press, 1990.  Paperback, 127 pp.  ISBN
0-89471-741-3.  $8.95.  Has a bibliography and lists of sources for
greenhouses, lighting and hydroponics supplies.  It includes two
recipes for nutrient solutions.

The book "How to Build and Use Greenhouses" Ortho Books, 1978. $7.95.
Has a section on hydroponics, including instructions for building
growing beds and pump systems, as well as greenhouses and indoor
lighting (does not include halide or sodium lighting; the book is
somewhat old).

A quick look in the latest National Gardening finds the following
suppliers:

  Hydrofarm Gardening Products    1-800-634-9999 (Hydrofarm West, CA)
                                  1-800-227-4567 (Hydrofarm East, PA)
  Worm's Way                      1-800-274-9676
  Diamond Hi Tech Indoor/Outdoor Gardening (HID lighting)
                                  1-800-331-3994
                                  In CA, (415) 459-3994
  Superior Growers Supply, Inc.   1-800-227-0027
  Cropking, Inc.                   (216) 725-5656

Aquaculture Magazine is a good source of advertisements from U.S. equipment
suppliers.  They have a reader response card you can send in for information
from any of their advertisers.  It costs $21 / year for 6 issues sent to
Canada (less I think for the U.S.).  There is also a yearly buyer's guide
for $15.  You can order using a credit card by calling 704-254-7334.

Also call Argent at 1-800-426-6258 and ask for their free catalogue and
their book catalogue.  They have aquaculture chemicals and equipment, and
an extensive selection of books.

--*--
Best book I have found on aquaculture is

Huet, Marcel. Textbook of Fish Culture: Breeding and Cultivation
of Fish, Eyre & Spottiswoode Ltd at Thanet Press, Margate, UK
1971, ISBN  o/85238/020/8

Has special sections on carp, pike, trout, perch, catfish, eels.
And sections of building dams, feeding, and the usual.
Organization: Iowa State University, Ames, IA
Mike Campbell is a graduate student in the Agricultural Education & Studies
department here.  He has experience and a great interest in aquaculture,
biodynamics and alternative agriculture.  He is currently working on
developing a curriculum in aquaculture under a fairly sizeable grant
received by his department.  He is not on the net, but if you wish to
contact him, call the AgEdS main office here and ask for him: 515-294-5904.

--*--

"Growing Edge" magazine, Indoor & Outdoor Gardening for Today's Grower

This month's issue, Vol. 3 #4, Summer, 1992 is especially interesting;
it has an article on combining aquaculture with hydroponics and another one on
biologically-intensive waste treatment systems; + many other
useful articles and advertisements. It's an amazing magazine albeit expensive/
size. For those interested in setting up electronic/electromechanical/
computer-based environmental control systems
to handle such things as soil moisture/humidity/temperature/air gas levels,
etc. there is an ongoing series of articles dealing with this topic complete
with construction plans, computer software, whole systems design-construction-
maintenance and materials/equipment/parts access info.

Subscription info:

The Growing EDGE
P.O. Box 1027
Corvallis, OR 97339
1-503-757-0027

U.S. delivered via 1st class smail and Canadian: $24.95, 1 year/4 issues
U.S. non-1st class smail:
     $17.95 - 1 year/4 issues
     $34.00 - 2 years/8 issues


They also have interesting books for sale such as:

"Gardening Indoors" George F. Van Patten
"Gardening: the Rockwool Book" George F. Van Patten
"The Hydroponic Hot House" James B. DeKorne

--------
I need a publication dealing with greenhouse propagation of vegetable
seedlings; let me know if you run across a good one.

Article 780 (15 more) in bionet.plants:
From: gilles.laberge@synapse.org (Gilles Laberge) 
ubject: Hydroponics & CO2
Date: 4 Jan 93 01:16:00 GMT
Distribution: world
Organization: SYNAPSE BBS - GATINEAU, QUEBEC - 819-561-4321
Lines: 23

To: mffowler@zeus.calpoly.edu (Michael Francis Fowler)
From: gilles.laberge@synapse.org
Date: 4 Jan 93 1am EST

MF>Oh...Since I am here-  I am curious what the effects 
MF>of supplementing Carbon Dioxide to my greenhouse
MF>crop of flowers and vegetables.  Any suggestions 
MF>about this is also greatly appreciated.   

Well I think that supplementing CO2 will increase the
"Greenhouse effect" in the closed stucture which will
increase the ambient temperature. This will throw off the
flowers natural cycle and have an effect contrary to what 
your looking for (more growth, longer bloom periods).

                                       G.L.
                                       Ottawa,Canada

Article 781 (15 more) in bionet.plants:
From: ajt@rri.sari.ac.uk (Tony Travis)
ubject: Re: Hydroponics & CO2Date: 4 Jan 93 10:28:32 GMT
Distribution: bionet
Organization: Rowett Research Institute

In article <9313232241.MIN-LRPBa00330.bionet-news@uk.ac.daresbury> you wrote:
: I am a Aeroponics/Hydroponics hobbyist.  Currently

I'm showing my ignorance here (again) but what is Aeroponics?

: I study Horticulture in college.  I am curious about
: careers in these related fields.  Any information
: about these would be greatly appreciated.  Thanks.

Did you cross-post this to bionet.jobs?

: Oh...Since I am here-  I am curious what the effects 
: of supplementing Carbon Dioxide to my greenhouse
: crop of flowers and vegetables.  Any suggestions 
: about this is also greatly appreciated.   

Elevated levels of CO2 are generally regarded as beneficial in a
greenhouse but if you are burning fuel to produce the CO2 you should be
aware that SO2 and NOX (various oxides of nitrogen) are also produced
which may have an adverse effect on your crop.

Even if you are burning 'clean' low-sulphur fuel you will get NOX
production if the air in the greenhouse comes into contact with hot
surfaces.  This is one reason why the best greenhouses are heated by
steam pipes.

There was some work done at Fairfield Experimental Station near Kirkham
in the UK during the 1970's concerning the relative merits of heating
the greenhouse compared to just heating the solution used to irrigate
the roots of plants grown using hydroponics.  Sadly, Fairfield closed
down years ago, but I'm sure the work was published.

        Tony.
--
Dr. A.J.Travis,                       |  Tony Travis
Rowett Research Institute,            |  JANET: <ajt@uk.ac.sari.rri>
Greenburn Road, Bucksburn,            |  other: <ajt@rri.sari.ac.uk>
Aberdeen, AB2 9SB. UK.                |  phone: 0224-712751

From: Roland.Gronroos@sgen.slu.se (Roland Gronroos)
ubject: Re: Hydroponics & CO2Date: 4 Jan 93 10:33:58 GMT
Followup-To: bionet.plants
Organization: Swedish University of Agricultural Sciences

In article <1993Jan03.232313.1313548@zeus.calpoly.edu>,
mffowler@zeus.calpoly.edu (Michael Francis Fowler) wrote:

> Oh...Since I am here-  I am curious what the effects 
> of supplementing Carbon Dioxide to my greenhouse
> crop of flowers and vegetables.  Any suggestions 
> about this is also greatly appreciated.   
> 

Carbon dioxide (CO2) fertilization is a common way to increase growth in
greenhouses.

I have tested the effect of CO2 on pine seedlings (Pinus sylvestris) there
was an increase in growth (DW increase) up to about 3500 ppm.

The following examples is cited from a brochure from (snail mail adress)
AGA GAS AB, S-17282 Sundbyberg, SWEDEN. They sell gas and equipment for CO2
fertilization.

Plant        ppm CO2     comment

Tomato      1000-1500   faster growth, earlier and larger yield (25-30%)  
Cucumber    1000-1500   faster growth, earlier and larger yield (25-30%)

Roses        1000       Larger yield, better stem and flower quality

Saintpaulia 1000-2000   Faster growth (24-62%), 1-2 weeks earlier flowering
                        , more flowers  
       
Atmosperic concentration is 300-400 ppm CO2.
In a closed greenhouse will the CO2 concentration drop to about 100-150 ppm
this retards growth.
Effects on man can be observed at 20000-30000 ppm CO2 after some hours
exposure. The authorities in Sweden regard 5000 ppm as safe for workers
spending  all their working-hours in greenhouse.

ubject: Aeroponics
From: mffowler@zeus.calpoly.edu (Michael Francis Fowler)
Date: Mon, 04 Jan 1993 18:58:13 GMT
Organization: California Polytechnic State University, San Luis Obispo
Lines: 10

Someone asked what aeroponics was.  Well, it's the method, developed in
Israel, that suspends the root system in an enclosed casing ( or
whatever) and mists the roots.  Larger plants with smaller root systems
have been achieved by this method.  I grow tomatoes this way and have
been successful in growth of 3 inches per day and by doing this I have
sped up the growth time a couple of weeks.  But, this technique is even
less forgiving than hydroponics.  Any other comments anyone?  Please
add.
                                        mffowler@nike.calpoly.edu

rticle 786 (12 more) in bionet.plants:
From: samodena@csemail.cropsci.ncsu.edu (S. A. Modena)
ubject: Re: Hydroponics & CO2
Organization: Crop Science Dept., NCSU, Raleigh, NC 27695-7620
Distribution: bionet
Date: Mon, 4 Jan 1993 20:07:33 GMT
Lines: 34

In article <1993Jan4.104210.24053@gserv1.dl.ac.uk> ajt@rri.sari.ac.uk writes:
>In article <9313232241.MIN-LRPBa00330.bionet-news@uk.ac.daresbury> you wrote:
>
>: Oh...Since I am here-  I am curious what the effects 
>: of supplementing Carbon Dioxide to my greenhouse
>: crop of flowers and vegetables.  Any suggestions 
>: about this is also greatly appreciated.   
>
>Elevated levels of CO2 are generally regarded as beneficial in a
>greenhouse but if you are burning fuel to produce the CO2 you should be
>aware that SO2 and NOX (various oxides of nitrogen) are also produced
>which may have an adverse effect on your crop.

Let's remember a bigger threat: incomplete combustion may produce
ETHYLENE......a plant hormone related to....undesirable "timing" effects
in greenhouses.

>Dr. A.J.Travis,                       |  Tony Travis

Article 790 (17 more) in bionet.plants:
From: Roland.Gronroos@sgen.slu.se (Roland Gronroos)
ubject: Re: Aeroponics
Date: 5 Jan 93 08:03:09 GMT
Followup-To: bionet.plants
Organization: Swedish University of Agricultural Sciences
Lines: 23

In article <C0CKvF.CyE@iat.holonet.net>, timper@iat.holonet.net (Tim
Perkis) wrote:
> 
> Can you recommend any references on aeroponics?

The review article:
Therory and techniques for steady state mineral nutrition and growth of
plants.
T Ingestad & A-B Lund 1986. Scandinavian Journal of Forest Research
1:439-453.

Matematical theory, culture and stock solutions, growth units and plants is
described in this paper. 

From rfrench@cs.stanford.edu Sun Feb 14 12:17:25 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA05467; Sun, 14 Feb 93 00:35:32 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA02198; Sat, 13 Feb 93 21:33:25 -0800
Date: Sat, 13 Feb 93 21:33:25 -0800
Message-Id: <9302140533.AA02198@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Hydroponics books
Status: RO
X-Status: 


Ok, we've now reached 20 list members and zero messages, so I thought
I'd start something.  (Many of the people on this list have indicated
that they're total beginners at this, so please don't be shy about
asking questions.  I'm sure the info will be useful to everyone.)

I've used the following two books for all my hydroponics information
so far.  Does anyone have any suggestions for other good books?

Richard E. Nicholls, "Beginning Hydroponics: Soilless Gardening",
Running Press Books.  I found this an excellent introduction.

Raymond Bridwell, "Hydroponic Gardening", Woodbridge Press.  This is
touted as the "number 1 book" but I found it very hard to extract
specific information from; he has a rambling conversational style that
I find somewhat annoying.




From rfrench@cs.stanford.edu Sun Feb 14 22:24:08 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA12381; Sun, 14 Feb 93 20:18:01 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA11334; Sun, 14 Feb 93 17:16:42 -0800
Date: Sun, 14 Feb 93 17:16:42 -0800
Message-Id: <9302150116.AA11334@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: [Z: Re:  Hydroponics books]
Status: RO
X-Status: 


I'll see if I can add an automatic Reply-To: line somehow...

----- Begin Forwarded Message
Date: Sun, 14 Feb 93 19:48:17 EST
From: uaturoff@king.mcs.drexel.edu (Z)
To: rfrench@cs.stanford.edu
Subject: Re:  Hydroponics books

(will a standard bounceback message hit the rest of the mailing list? -Z.)

> I've used the following two books for all my hydroponics information
> so far.  Does anyone have any suggestions for other good books?
> 
> Richard E. Nicholls, "Beginning Hydroponics: Soilless Gardening",
> Running Press Books.  I found this an excellent introduction.
> 
> Raymond Bridwell, "Hydroponic Gardening", Woodbridge Press.  This is
> touted as the "number 1 book" but I found it very hard to extract
> specific information from; he has a rambling conversational style that
> I find somewhat annoying.
> 

I don't have the specific reference off hand, but I am still thoroughly 
convinced that this is the bible of hydroponics.
(from the Library of Congress catalog):

     LC Call Number: SB126.5 .R47 1989

             Author: Resh, Howard M.

              Title: Hydroponic food production : a definitive guidebook of
                      soilless food growing methods / by Howard M. Resh.

            Edition: 4th ed.
   Publication Info: Santa Barbara, Calif. : Woodbridge Press Pub. Co., c1989.
  Phys. Description: 462 p. : ill. ; 24 cm.

              Notes: "For the professional and commercial grower and the
                      advanced home hydroponics gardener."

He seems to be very thorough with his presentation of the topic, not missing
anything important.  Unfortunately, I haven't yet been able to add this book
to my library, since it's $34.95, and the way he's been updating the book, 
I wouldn't be surprised to see a 5th edition sometime this calendar year.

At this point, I've had to just hunt for it and drool over it.  

Z.
uaturoff@mcs.drexel.edu



----- End Forwarded Message

From den0@lehigh.edu Tue Feb 16 23:51:29 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA28697; Tue, 16 Feb 93 14:07:35 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA02692; Tue, 16 Feb 93 11:04:46 -0800
Received: by ns2.CC.Lehigh.EDU id AA36265
  (5.65c/IDA-1.4.4 for hydro@hawg.stanford.edu); Tue, 16 Feb 1993 13:37:39 -0500
Message-Id: <199302161837.AA36265@ns2.CC.Lehigh.EDU>
Date: Tue, 16 Feb 1993 13:37:37 EST
From: den0@lehigh.edu (DEAN E. NELSON)
Subject: Constant circulation
To: hydro@Hawg.Stanford.EDU
Status: RO
X-Status: 

>From what I've read, most hydroponic systems flood the aggregate, and then
let it drain.  This is done periodically.  Since I want to integrate my system
with a constant flow filter system for a large tank of fish, I would like to
use a hydroponic system that uses a constant flow of water.  I have read about
systems that mist the roots, and also wick systems.  But, what I've read
doesn't provide any details about materials, etc.

I would appreciate any leads on sources of information.

Perhaps some of you may be interested in my project, which I have been
planning for the last 6 months or so.  My wife raises rabbits (around 50)
and several years ago, I started raising worms in the manure pits under their
cages.  This last summer, I built a shelter for worm beds outside, because the
conditions which are best for worms are best for rabbits.  The worms have been
quite successful.  I am planning to start selling them this spring as bait,
but I also wanted to find other uses.  One idea was to use them as food for
fish that we could then eat.

I have found a lot of information on raising fish, and have decided to put a
tank (3'x6'x21') inside a quonset greenhouse (made from PVC piping and
plastic) and incorporate a hydroponic garden into the filtering system.  I
would be happy to hear from anyone who has done anything similar, or that
would like to. It would be nice to avoid as many mistakes as possible the first
time around.

Dean Nelson
den0@lehigh.edu


From time@ice.com Tue Feb 16 23:55:37 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA11276; Tue, 16 Feb 93 20:22:22 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA09874; Tue, 16 Feb 93 17:19:34 -0800
Received: by heifetz.msen.com (/\==/\ Smail3.1.22.1 #22.11)
	id <m0nOdPq-000Hd5C@heifetz.msen.com>; Tue, 16 Feb 93 20:17 EST
Received: by tbomb.ice.com (uA-1.7b6); Tue, 16 Feb 93 18:17:12 EST
From: time@ice.com (Tim Endres)
To: den0@lehigh.edu
Subject: Re: Constant circulation
Date: Tue, 16 Feb 93 18:17:12 EST
Cc: hydro@Hawg.Stanford.EDU
Organization: ICE Engineering, Inc.
Reply-To: time@ice.com (Tim Endres)
Message-Id: <1CE00001.qdo175@tbomb.ice.com>
X-Mailer: uAccess - Macintosh Release: 1.7b6
Status: RO
X-Status: 


In Regards to your letter <199302161837.AA36265@ns2.CC.Lehigh.EDU>:
> >From what I've read, most hydroponic systems flood the aggregate, and then
> let it drain.  This is done periodically.  Since I want to integrate my system
> with a constant flow filter system for a large tank of fish, I would like to
> use a hydroponic system that uses a constant flow of water.  I have read about
> systems that mist the roots, and also wick systems.  But, what I've read
> doesn't provide any details about materials, etc.
> 
> I would appreciate any leads on sources of information.
> 
> Perhaps some of you may be interested in my project, which I have been
> planning for the last 6 months or so.  My wife raises rabbits (around 50)
> and several years ago, I started raising worms in the manure pits under their
> cages.  This last summer, I built a shelter for worm beds outside, because the
> conditions which are best for worms are best for rabbits.  The worms have been
> quite successful.  I am planning to start selling them this spring as bait,
> but I also wanted to find other uses.  One idea was to use them as food for
> fish that we could then eat.
> 
> I have found a lot of information on raising fish, and have decided to put a
> tank (3'x6'x21') inside a quonset greenhouse (made from PVC piping and
> plastic) and incorporate a hydroponic garden into the filtering system.  I
> would be happy to hear from anyone who has done anything similar, or that
> would like to. It would be nice to avoid as many mistakes as possible the first
> time around.
> 
> Dean Nelson
> den0@lehigh.edu


The system that you want is a gravity feed system. You set your plants
in a trench ( can be plastic above ground or in ground lined) that
returns the water to your resevoir. The trench is lined in black plastic
(roots need dark I think) and capillary matting is layed on the bottom.
The plants are started in rock wool cubes and set in as soon as roots
appear. The flow is a set speed ( drip rate) that must be controlled
. The nutriet stream just constantly flows over the roots. Victory
Gardens just visited a place that had this system. I also have used
it. I haven't however used fish nutrients. The plants are rather particular
on the combination of chemicals because you are main-linning them.
You may have to pump the water in to a resivior and adjust the balance.


Please let me know how you are doing. I have wanted to try this but
you really can't do it on a small scale. ( at least I couldn't find
a way). Any info you can pass my way would be appreciated.
Thanks 
Karen
kareb@ice.com
> 


tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)

USENET - a slow moving self parody... ph

From uaturoff@king.mcs.drexel.edu Mon Feb 22 11:54:21 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA08114; Mon, 22 Feb 93 11:43:19 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA27684; Mon, 22 Feb 93 08:40:33 -0800
Received: from tweedle.mcs.drexel.edu ([129.25.7.203]) by mcs.drexel.edu (4.1/SMI-4.0)
	id AA15050; Mon, 22 Feb 93 11:38:16 EST
Date: Mon, 22 Feb 93 11:38:16 EST
From: uaturoff@king.mcs.drexel.edu (Z)
Message-Id: <9302221638.AA15050@mcs.drexel.edu>
To: hydro@Hawg.Stanford.EDU
Subject: Research Programs...
Status: RO
X-Status: 

One of the things I've been seriously considering is getting into a graduate
level program in hydroponics.  The problem with this is that I have yet to
find such a program.  I think that the reasons is either (1) it's too
lightweight to become a college-level program, or (2) not enough people
know enough about Hydroponics to offer a decent offering of courses.

I know that some serious research is going on.  I remember reading about 
a program recently partially funded by the Namibian government to take small`
plots of ground, and raise food and tilapia fish, so that both the fish and
the plants are being managed symbiotically.  Apparently, this research project
is being done by a private group.  

Ideally, working in such a setting would be better than going to school if only
because I'd be making money rather than spending it.  But I think that 
credentials are sufficiently important and that the word has to be spread
about hydroponics that I'd be willing to put up with a university environment
(read: university stipend) to do some decent (first time) research.

Any comments?

Adam.
uaturoff@mcs.drexel.edu

From rfrench@cs.stanford.edu Tue Mar  2 20:30:45 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA16493; Tue, 2 Mar 93 19:17:47 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA01807; Tue, 2 Mar 93 16:15:10 -0800
Date: Tue, 2 Mar 93 16:15:10 -0800
Message-Id: <9303030015.AA01807@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Vegetables with small root systems?
Status: RO
X-Status: 


One of the worst things I've done recently is clean the roots from
last year's crop out of my hydroponics system.  Cleaning tomato and
corn roots from 100 gal. of pebbles (by taking them out 1/4 gal at a
time and separating the roots by hand) is really obnoxious.  What are
some good vegetables to grow that develop SMALL root systems?

			Rob


From uaturoff@king.mcs.drexel.edu Tue Mar  2 20:31:02 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA16651; Tue, 2 Mar 93 19:29:03 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA01863; Tue, 2 Mar 93 16:26:07 -0800
Received: from oyster10.mcs.drexel.edu ([129.25.7.115]) by mcs.drexel.edu (4.1/SMI-4.0)
	id AA22242; Tue, 2 Mar 93 19:23:04 EST
Date: Tue, 2 Mar 93 19:23:04 EST
From: uaturoff@king.mcs.drexel.edu (Z)
Message-Id: <9303030023.AA22242@mcs.drexel.edu>
To: hydro@Hawg.Stanford.EDU
Subject: Limitations of hydroponic systems....
Status: RO
X-Status: 


It seems to me that the whole theory/practice behind hydroponics would allow
any kind of environment to be reproduced at will.  Case in point: Biosphere2.

I remember reading recently that it is impractical to raise grains (wheat,
rice, etc.) in a greenhouse environment because the plants are too finicky.
Then again, there is the question: Why would you _want_ to do this if
you have Kansas....

Which leads to my question.  Is there anything inherently difficult about
raising grains that would prevent such a greenhouse effort?  Does the 
greenhouse/hydroponic approach give any benefit that isn't being investigated?

Hope this isn't _too_ vague.....

Z.

From i919802@redgum.ucnv.edu.au Tue Mar 16 23:16:55 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA13866; Tue, 16 Mar 93 17:01:22 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA17381; Tue, 16 Mar 93 13:58:06 -0800
Received: by redgum.ucnv.edu.au id AA25478
  (5.65c/IDA-1.3.5 for hydro@hawg.stanford.edu); Wed, 17 Mar 1993 07:58:31 +1000
From: Dougie <i919802@redgum.ucnv.edu.au>
Message-Id: <199303162158.AA25478@redgum.ucnv.edu.au>
Subject: First try not the best :(
To: hydro@Hawg.Stanford.EDU (hydroponics mail-list)
Date: Wed, 17 Mar 93 7:58:30 EST
X-Mailer: ELM [version 2.3 PL5]
Status: RO
X-Status: 

  A few months ago I decided to try out a hydroponics system to grow
tomatoes. The system consisted of a 10" deep tub which was filled with a
commercial nutrient solution (apparently pH buffered) and a wire frame
on top which was covered with a layer of grow-wool. The plants were
anchored to this frame and approximately half of the root system was
submerged in the solution. At the bottom of the tub were a couple of
aquarium airstones hooked to an airpump to supply root aeration. This
system seemed to work well for a couple of days. But after about a week,
the new leaves formed seemed to be distorted. They were not of the
proper shape and were very shiny. I decided to give up on the idea for
a while but now I would like to try again. However, I do not know what I
did wrong last time and would like to resolve these problems before I
build a larger system. There was no sign of algae growth or anything in
the tub after the week, so I am at loss to explain what happened. Does
anyone know what I did wrong?

Dave.

From Snyder_Larry%Clearwater@ccmail.timeplex.com Wed Mar 17 17:44:37 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA19797; Wed, 17 Mar 93 15:16:00 EST
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA27530; Wed, 17 Mar 93 11:33:20 -0800
Registered-Mail-Reply-Requested-By: Snyder_Larry%Clearwater@CCMAIL.TIMEPLEX.COM
Received: from CCMAIL.TIMEPLEX.COM by sys30.timeplex.com (PMDF #2740 ) id
 <01GVX2E2GX808WWCJS@sys30.timeplex.com>; Wed, 17 Mar 1993 14:33:26 EST
Date: 17 Mar 1993 14:23 -0500
From: Snyder_Larry%Clearwater@ccmail.timeplex.com
Subject: Hydroponics Using Sea Salts and Sea Water
To: hydro@Hawg.Stanford.EDU
Message-Id: <01GVX2E2J2DU8WWCJS@sys30.timeplex.com>
Mime-Version: 1.0
Content-Transfer-Encoding: 7BIT
Status: RO
X-Status: 

I have interest in using Sea Salts and/or Sea Water to do hydroponiocs.  My idea
is to use the Sea Salts or Water to provide trace elements to the plants.  If 
any on has information on this subject please provide it to me.  Be new to this 
group I look forward to networking with you all.  I am located in the Tampa 

From rfrench@cs.stanford.edu Sat Apr 10 21:57:00 1993
Received: from Hawg.Stanford.EDU by SunSite.unc.edu (4.1/TAS/11-16-88)
	id AA25327; Sat, 10 Apr 93 21:44:10 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA21375; Sat, 10 Apr 93 18:42:16 -0700
Date: Sat, 10 Apr 93 18:42:16 -0700
Message-Id: <9304110142.AA21375@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Starting a new year...
Status: RO
X-Status: 


Well, for what it's worth, I've started my hydroponics garden for the
year.  Over the winter I cleaned it out and sterilized it with
chlorine, so hopefully the plants will be happier this year.  So far I
have planted 9 Burpee's Breeder's Choice yellow corn and two Ace
tomatoes.

The local tap water has a pH of 9.2, so I'm using MirAcid as my
nutrient.  This brings it down to around 7.5, which isn't TOO bad.
Maybe I'll try a mild acidifier (like General Hydroponics' "pH Down")
if I have problems.

			Rob

From rfrench@cs.stanford.edu  Ukn Jul  8 14:55:11 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA09092; Thu, 8 Jul 93 14:55:10 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA25442; Thu, 8 Jul 93 11:51:54 -0700
Date: Thu, 8 Jul 93 11:51:54 -0700
Message-Id: <9307081851.AA25442@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: [claude@oligojo.login.qc.ca: Re: subscribe...ok...]
Status: RO
X-Status: 


Please be sure to send messages intended for the entire list to
hydro@hawg.stanford.edu...thanks.

		Rob

----- Begin Forwarded Message
From: claude@oligojo.login.qc.ca
Subject: Re: subscribe...ok...
To: rfrench@cs.stanford.edu (Robert S. French)
Date: Wed, 7 Jul 1993 22:21:19 +0000 (GMT)
In-Reply-To: <9307071800.AA07490@Hawg.Stanford.EDU> from "Robert S. French" at Jul 7, 93 11:00:27 am

First to start a discussion we need to know what species are cultivated by
all others. Myself i dont produce but my job is to give advice to commercial
grower in greenhouse production and ofcourse in hydroponic production. i
think that hydroponic is the most chalenging production technic because
there is no place for mistake. we must control every element because a
slight variation can leed to big trouble very fast. But that production
technic is the one that produce the best result and the bigest yield.

I have to work with many vegetable crop and also ornamental plant. they are
produced in recirculated solution or lost solution. the latest is the one
that give less trouble. My main interest is in the solution control and i
try to find every information i can on how plant absorb fertiliser and how
one element can interfere with another one. Right now am looking to improove
fertiliser ratio for herbs, in order to get better yield without loosing the
taste, witch is very important. 

so what type of plant do you grow...

thanks

Claude 


----- End Forwarded Message

From rfrench@cs.stanford.edu  Ukn Jul  8 15:01:36 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA09480; Thu, 8 Jul 93 15:01:33 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA25476; Thu, 8 Jul 93 11:56:55 -0700
Date: Thu, 8 Jul 93 11:56:55 -0700
Message-Id: <9307081856.AA25476@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Current status for this season
Status: RO
X-Status: 


Well, so far my hydro gardening attempts for this season haven't been
so great.  For those of you who tuned in late, I have a large
fiberglass garden with an automatic recirc pump and 40 gal solution
capacity.  It recircs twice a day.  The garden is outdoors and not
enclosed.  This came with the place I'm currently renting, so I'm
guessing about how to use it.

So far, I have tried to grow corn and tomatoes.  I use a nutrient
solution consisting of MirAcid at recommended strength (the local
water has a pH of around 9.2, and MirAcid makes it almost neutral).  
The first batch of corn had a big problem -- the local cats kept
eating it.  So it never grew very tall.  It's now about 1' tall and
already producing tassels.  I just planted a new batch and will try to
keep the cats away this time.

The tomatoes usually do better, although their leaves tend to turn
yellow and curl up after awhile.  I imagine it's a nutrient imbalance
of some sort.

An interesting observation is that I drained the system and let it sit
for a few days with no solution running through it (I was too busy to
refill it).  The plants actually grew BETTER during this time.  So,
taking the hint that perhaps I was giving it too much nutrient, I cut
the dose by half with the next batch and so far the plants are growing
well.

			Rob

From claude@oligojo.login.qc.ca  Ukn Jul  8 22:53:50 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA28071; Thu, 8 Jul 93 22:53:48 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA26520; Thu, 8 Jul 93 19:51:09 -0700
Received: from oligojo by comback.login.qc.ca with uucp
	(Smail3.1.28.1 #4) id m0oE8fh-0000JwC; Thu, 8 Jul 93 22:58 EDT
Received: by oligojo.login.qc.ca (Smail3.1.28.1 #6)
	id m0oE4kx-0000RsC; Thu, 8 Jul 93 22:47 GMT
Message-Id: <m0oE4kx-0000RsC@oligojo.login.qc.ca>
From: claude@oligojo.login.qc.ca
Subject: Current status for this season (fwd)...
To: hydro@Hawg.Stanford.EDU (culture hydroponique)
Date: Thu, 8 Jul 1993 22:47:59 +0000 (GMT)
X-Mailer: ELM [version 2.4 PL21]
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 2108      
Status: RO
X-Status: 

 > Well, so far my hydro gardening attempts for this season haven't been
> so great.  For those of you who tuned in late, I have a large
> fiberglass garden with an automatic recirc pump and 40 gal solution
> capacity.  It recircs twice a day.  The garden is outdoors and not
> enclosed.  This came with the place I'm currently renting, so I'm
> guessing about how to use it.
> 
> So far, I have tried to grow corn and tomatoes.  I use a nutrient
> solution consisting of MirAcid at recommended strength (the local
> water has a pH of around 9.2, and MirAcid makes it almost neutral).  
> The first batch of corn had a big problem -- the local cats kept
> eating it.  So it never grew very tall.  It's now about 1' tall and
> already producing tassels.  I just planted a new batch and will try to
> keep the cats away this time.
>
To get more from your nutrient solution you should lower the pH to about 6.0
or most micro-nutrient wont be available to plant.

Water with a pH of 9.2 is probably full of sodium so you need to be carefull
when you feed the plant because too much fertiliser will raise the salinity
of the solution and even burns the root.
 
> The tomatoes usually do better, although their leaves tend to turn
> yellow and curl up after awhile.  I imagine it's a nutrient imbalance
> of some sort.
> 
> An interesting observation is that I drained the system and let it sit
> for a few days with no solution running through it (I was too busy to
> refill it).  The plants actually grew BETTER during this time.  So,
> taking the hint that perhaps I was giving it too much nutrient, I cut
> the dose by half with the next batch and so far the plants are growing
> well.
> 
> 			Rob
> 

For the tomatoes, it's probably because of a too high pH and the plant dont
get all micro nutrient it's need. Also at a ph of around 7.0, nitrogen is
less available and that's why you get yellow leaves after a period of time.

Normally if lower leaves turn yellow you need more nitrogen, if it's the top
leaves it's a micro nutrients deficiency. Could you tel more about your
yellow leaves. 

thanks,  Claude

From rfrench@cs.stanford.edu  Ukn Jul  9 18:03:03 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA08451; Fri, 9 Jul 93 18:03:00 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA13925; Fri, 9 Jul 93 15:00:41 -0700
Date: Fri, 9 Jul 93 15:00:41 -0700
Message-Id: <9307092200.AA13925@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: claude@oligojo.login.qc.ca
Cc: hydro@Hawg.Stanford.EDU
In-Reply-To: claude@oligojo.login.qc.ca's message of Thu, 8 Jul 1993 22:47:59 +0000 (GMT)
	<m0oE4kx-0000RsC@oligojo.login.qc.ca>
Subject: Re: Current status for this season (fwd)...
Status: RO
X-Status: 

   From: claude@oligojo.login.qc.ca
   Date: Thu, 8 Jul 1993 22:47:59 +0000 (GMT)

   To get more from your nutrient solution you should lower the pH to about 6.0
   or most micro-nutrient wont be available to plant.

Do you have a suggestion about how to do this?  My experience in the
past, with what little chemistry I know, is that the water is pretty
well buffered, and whenever I add an acid it simply precipitates out.
There is a product called "pH down" by General Hydroponics that I
could pick up and try.

How often would you suggest changing the solution?  There are 40 gal
of solution, and only 9 corn and 1 tomato plant growing in it.  Much
is lost to transpiration every day.  Is it sufficient to just
re-dilute it with tap water (and adjust the pH) or are nutrients being
lost at the same time?

   For the tomatoes, it's probably because of a too high pH and the plant dont
   get all micro nutrient it's need. Also at a ph of around 7.0, nitrogen is
   less available and that's why you get yellow leaves after a period of time.

   Normally if lower leaves turn yellow you need more nitrogen, if it's the top
   leaves it's a micro nutrients deficiency. Could you tel more about your
   yellow leaves. 

So far this year my leaves aren't yellow.  They were yellow last year.
It was, I believe, the lower leaves that turned yellow.  They would
also become dry and "crunchy" after a while.

			Rob

From claude@oligojo.login.qc.ca  Ukn Jul 13 09:44:36 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA07531; Tue, 13 Jul 93 09:44:34 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA21002; Mon, 12 Jul 93 21:18:15 -0700
Received: from oligojo by comback.login.qc.ca with uucp
	(Smail3.1.28.1 #4) id m0oFbwa-0000MZC; Tue, 13 Jul 93 00:26 EDT
Received: by oligojo.login.qc.ca (Smail3.1.28.1 #6)
	id m0oFXYI-0000W9C; Mon, 12 Jul 93 23:44 GMT
Message-Id: <m0oFXYI-0000W9C@oligojo.login.qc.ca>
From: claude@oligojo.login.qc.ca (Claude Gelinas Agr.)
Subject: Re: Current status for this season (fwd)... (fwd)
To: hydro@Hawg.Stanford.EDU (culture hydroponique)
Date: Mon, 12 Jul 1993 23:44:58 +0000 (GMT)
X-Mailer: ELM [version 2.4 PL21]
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 3694      
Status: RO
X-Status: 

>    From: claude@oligojo.login.qc.ca
>    Date: Thu, 8 Jul 1993 22:47:59 +0000 (GMT)
> 
>    To get more from your nutrient solution you should lower the pH to about 6.0
>    or most micro-nutrient wont be available to plant.
> 
> Do you have a suggestion about how to do this?  My experience in the
> past, with what little chemistry I know, is that the water is pretty
> well buffered, and whenever I add an acid it simply precipitates out.
> There is a product called "pH down" by General Hydroponics that I
> could pick up and try.

to change the pH you have to find first how your water is buffered like you
say. The buffering capacity of the water is in fact the alkalinity or the
amount of bicarbonate and hydroxyde already dissolved in water. these
product will interfere with the action of any acid one will add to the
solution. To find the alkalinity level of the water, just use a tester kit
provided for swiming pool they are quite acurate and cost very few.
when you know the alkalinity of the water you just have to use a chart that
will tell you how much acid you need to add in order to break the alkalinity
and start to lower the pH. I'll send a chart for acid next day or as soon as
i have enough time.

Could you send me the technical information about the "pH down" product.
What type of acid is it. some are good for hydroponic and some dont.

> 
> How often would you suggest changing the solution?  There are 40 gal
> of solution, and only 9 corn and 1 tomato plant growing in it.  Much
> is lost to transpiration every day.  Is it sufficient to just
> re-dilute it with tap water (and adjust the pH) or are nutrients being
> lost at the same time?

normally you dont have to change the solution, but just add fresh solution
to refill the container. The only time you need to change the solution is
when there are some accumulation of ions such as sulphates SO4-- or sodium
that will raise the salt index and disturbe the plant nutrition. First to
know if you will need to change the solution very often you need to have
your water analysed for mineral and that can be done in any good water lab.

Each time you add new water you must add nutrient but during summer month
when transpiration is very high, the solution must be more diluted then
during winter. Normally during summer we use half strainght solution. That
prevent salt build-up. The pH must be adjusted each time and some time also
when you dont add a lot of water. that is because when plant absorb some
nutrient she exchange it with an H+ ions that will lower the pH of the
solution. if your pH tend to drop after few days, this is because you use to
much of ammonium nitrogen in your solution. Replace it with nitrate nitrogen
witch are exchanged with OH- ions when absorbed and these will raise the pH.
A good ratio will tend to keep pH almost stable.
> 
>    For the tomatoes, it's probably because of a too high pH and the plant dont
>    get all micro nutrient it's need. Also at a ph of around 7.0, nitrogen is
>    less available and that's why you get yellow leaves after a period of time.
> 
>    Normally if lower leaves turn yellow you need more nitrogen, if it's the top
>    leaves it's a micro nutrients deficiency. Could you tel more about your
>    yellow leaves. 
> 
> So far this year my leaves aren't yellow.  They were yellow last year.
> It was, I believe, the lower leaves that turned yellow.  They would
> also become dry and "crunchy" after a while.
> 
> 			Rob
> 

For your leaves it is mainly the nitrogen but also when you are almost ready
to harvest your first tomatoes you must increase the amount of potassium to
get 1.5 time the amount of nitrogen in your solution.


claude

From rfrench@cs.stanford.edu  Ukn Jul 19 16:18:05 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA11168; Mon, 19 Jul 93 16:18:04 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA06002; Mon, 19 Jul 93 13:13:18 -0700
Date: Mon, 19 Jul 93 13:13:18 -0700
Message-Id: <9307192013.AA06002@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: Yellowing of tomato leaves
Status: RO
X-Status: 


Ok, my otherwise healthy tomato plant has started to yellow like it
did last year.  It's a slight yellowing starting at the tips of the
leaves and proceeding inward.  The yellowing is between the veins,
which remain green.  There is also a slight curling of the leaves.My
solution pH is currently 5.4 (I have no idea how it go so acid).

Suggestions?

		Rob

From claude@oligojo.login.qc.ca  Ukn Jul 19 23:11:36 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA25895; Mon, 19 Jul 93 23:11:34 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA16447; Mon, 19 Jul 93 20:03:35 -0700
Received: from oligojo by comback.login.qc.ca with uucp
	(Smail3.1.28.1 #4) id m0oI87K-0000L1C; Mon, 19 Jul 93 23:11 EDT
Received: by oligojo.login.qc.ca (Smail3.1.28.1 #6)
	id m0oI3tR-0000WLC; Mon, 19 Jul 93 22:41 GMT
Message-Id: <m0oI3tR-0000WLC@oligojo.login.qc.ca>
From: claude@oligojo.login.qc.ca (Claude Gelinas Agr.)
Subject: more on yellow tomatoes
To: hydro@Hawg.Stanford.EDU (culture hydroponique)
Date: Mon, 19 Jul 1993 22:41:13 +0000 (GMT)
X-Mailer: ELM [version 2.4 PL21]
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 2175      
Status: RO
X-Status: 

>From claude Mon Jul 19 22:38:04 1993
Subject: Re: Yellowing of tomato leaves...
To: rfrench@cs.stanford.edu (Robert S. French)
Date: Mon, 19 Jul 1993 22:38:04 +0000 (GMT)
In-Reply-To: <9307192013.AA06002@Hawg.Stanford.EDU> from "Robert S. French" at Jul 19, 93 01:13:18 pm
X-Mailer: ELM [version 2.4 PL21]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 1748      

Hi, your ph is too low probably because you use the wrong type of nitrogen.
Your fertiliser solution contains too much of ammonium type nitrogen (NH4+)
and when your tomatoes absorb that type of nitrogen it in fact exchange it
with an H+ that drop your pH solution. Check the label on the fertilizer you
use. it must tell the type of nitrogen and how much of it is in the bag.

ex. the well known 20-20-20 soluble fertiliser have 12 units out of 20 from
urea, 6 units in NO3- and 2 in the NH4+ form and that information is supposed
to be written on the bag or available from your fertilizer dealer.

in hydroponic you must have 80% or more of the nitrogen in the nitrate form
(NO3-) and the remainder in NH4+  and absolutely no urea because it wont be
absorbed by the plant in hydroponic. Urea need to be broken by an enzyme
that is every where in the soil but absent in hydroponic.

So when your pH go down, raise the amount of NO3- in your fertiliser
solution.


The yellowing may be the result of that low ph because at that ph some
micronutrients are not well absorbed by your plant. tel me more about your
yellow leaf. If it's the new one, it's a micronutrient deficiency, probably
iron. By the way, what is the weather since few days at your place, because
real high temperature could induce iron or manganese deficiency that will
last for about two weeks and will turn the head of your plant yellow in just
few hours. If it's the problem spray leaves with iron or manganese sulphate
or chelate to overcome that problem at about 100 ppm solution.

If it's the old leaves the nitrogen is the problem and the low pH is
the thing to check.


I'll check in my note and send you a description of symptoms for each
deficiency in few days.

Claude 

From schuch@bopper2.phx.mcd.mot.com  Ukn Aug  2 13:06:27 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA25412; Mon, 2 Aug 93 13:06:25 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA16518; Mon, 2 Aug 93 09:59:59 -0700
Received: by bopper2.phx.mcd.mot.com (5.61/MCDMAIL IR04 [07/23/90 15:51]/1.34.bopper2)
	id AA06280; Mon, 2 Aug 93 09:55:25 -0700
From: schuch@bopper2.phx.mcd.mot.com (John Schuch)
Message-Id: <9308021655.AA06280@bopper2.phx.mcd.mot.com>
Subject: hydroponic questions
To: hydro@Hawg.Stanford.EDU
Date: Mon, 2 Aug 93 9:55:11 MST
X-Mailer: ELM [version 2.2 PL10]
Status: RO
X-Status: 


Hello? Hello? Does this thing work?


I've been looking through a hydroponic catalog I received last week
and had a couple of questions possibly you could answer.

There are two products in question: The first is a ventilation system
made of thin polyethylene tubing which directs air right to the base
of the plant. The second is a nitrogen system which releases nitrogen
right on the plant. 

Now the question is, given that a greenhouse in Phoenix in the summer
would seem to need the coolers running full-tilt all day to keep the
thing from melting down :-), what good would either of those products
do?

With the tubing ventilation system, what does it do that a ceiling fan
could not?


John


-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602)438-3008 - CompuServe: 70733.3330  |
+--------------------------------------------------------------------------+

From rfrench@cs.stanford.edu  Ukn Aug  2 16:05:19 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA04656; Mon, 2 Aug 93 16:05:17 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA16964; Mon, 2 Aug 93 13:00:59 -0700
Date: Mon, 2 Aug 93 13:00:59 -0700
Message-Id: <9308022000.AA16964@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: schuch@bopper2.phx.mcd.mot.com (John Schuch)
Cc: hydro@Hawg.Stanford.EDU
In-Reply-To: John Schuch's message of Mon, 2 Aug 93 9:55:11 MST
	<9308021655.AA06280@bopper2.phx.mcd.mot.com>
Subject: Re: hydroponic questions
Status: RO
X-Status: 

   From: schuch@bopper2.phx.mcd.mot.com (John Schuch)
   Date: Mon, 2 Aug 93 9:55:11 MST


   Hello? Hello? Does this thing work?

I sure hope so :-)

   With the tubing ventilation system, what does it do that a ceiling fan
   could not?

Well, I'm going to take a random guess at this, which may or may not
be right.  Not all plants like to be submerged in water 24 hours a
day.  That's why many hydro systems fill up the aggregate and then let
it drain back out.  Likewise, that's why it's good to soak your soil
and then let it drain completely.  When you soak a medium, all the
spaces fill with water.  As the water drains, air is drawn down into
the soil.  You then have water clinging to soil/agg particles, with
air in between the particles.  This is the environment many plants
like to grow in.  My guess if this ventilation system is for supplying
roots with air under water.  It has nothing to do with cooling.

I didn't see a question about the nitrogen sprayer you mentioned.

			Rob

From rfrench@cs.stanford.edu  Ukn Aug  2 16:05:19 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA04656; Mon, 2 Aug 93 16:05:17 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA16964; Mon, 2 Aug 93 13:00:59 -0700
Date: Mon, 2 Aug 93 13:00:59 -0700
Message-Id: <9308022000.AA16964@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: schuch@bopper2.phx.mcd.mot.com (John Schuch)
Cc: hydro@Hawg.Stanford.EDU
In-Reply-To: John Schuch's message of Mon, 2 Aug 93 9:55:11 MST
	<9308021655.AA06280@bopper2.phx.mcd.mot.com>
Subject: Re: hydroponic questions
Status: RO
X-Status: 

   From: schuch@bopper2.phx.mcd.mot.com (John Schuch)
   Date: Mon, 2 Aug 93 9:55:11 MST


   Hello? Hello? Does this thing work?

I sure hope so :-)

   With the tubing ventilation system, what does it do that a ceiling fan
   could not?

Well, I'm going to take a random guess at this, which may or may not
be right.  Not all plants like to be submerged in water 24 hours a
day.  That's why many hydro systems fill up the aggregate and then let
it drain back out.  Likewise, that's why it's good to soak your soil
and then let it drain completely.  When you soak a medium, all the
spaces fill with water.  As the water drains, air is drawn down into
the soil.  You then have water clinging to soil/agg particles, with
air in between the particles.  This is the environment many plants
like to grow in.  My guess if this ventilation system is for supplying
roots with air under water.  It has nothing to do with cooling.

I didn't see a question about the nitrogen sprayer you mentioned.

			Rob

From time@ice.com  Ukn Aug  6 00:07:22 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA07025; Fri, 6 Aug 93 00:07:17 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA06586; Thu, 5 Aug 93 21:04:58 -0700
Received: by heifetz.msen.com (/\==/\ Smail3.1.22.1 #22.11)
	id <m0oOIsp-000HcyC@heifetz.msen.com>; Thu, 5 Aug 93 23:54 EDT
Received: by tbomb.ice.com (uA-1.7b6); Thu, 5 Aug 93 19:55:52 EST
From: time@ice.com (Tim Endres)
To: schuch@bopper2.phx.mcd.mot.com
Subject: Re: hydroponic questions
Date: Thu, 5 Aug 93 19:55:52 EST
Cc: hydro@Hawg.Stanford.EDU
Organization: ICE Engineering, Inc.
Reply-To: time@ice.com (Tim Endres)
Message-Id: <1CE00001.8e5i7d@tbomb.ice.com>
X-Mailer: uAccess - Macintosh Release: 1.7b6
Status: RO
X-Status: 


In Regards to your letter <9308021655.AA06280@bopper2.phx.mcd.mot.com>:
> There are two products in question: The first is a ventilation system
> made of thin polyethylene tubing which directs air right to the base
> of the plant. The second is a nitrogen system which releases nitrogen
> right on the plant. 

We have used many "atmosphere enhancement" mechanisms. The reality
of it, though, is that the atmosphere is the absolute last thing
that you really wish to worry about optimizing.

> Now the question is, given that a greenhouse in Phoenix in the summer
> would seem to need the coolers running full-tilt all day to keep the
> thing from melting down :-), what good would either of those products
> do?
> 
> With the tubing ventilation system, what does it do that a ceiling fan
> could not?

Nothing can do more for your plants than *strong* (I mean high capacity)
ventilation. Ventilation is more critical than many other things.
Thus, invest in an exhaust system that can exhaust a *lot* of air
in a short time. Combined with a reasonable source of cool air to
replace that which is exhausted, you will get about the best air
temperature control that you can want. One way to get good cool air
is to pull it from underground. Some people have run a heat duct
down through a deep ditch that they dug and buried. Others have run
it through cool water. In Pheonix, you may not have many options.

Also, under hot conditions, you need to be very concerned about the
temperature of the nutrient solution. Too hot, and the plants will
not be able to exchange nutrients well at the roots. Thus, I would
set up some system that allows you to have some control over the
nutrient solution's temperature. Even ice cubes added occasionally
can give you pretty good control.


tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)

USENET - a slow moving self parody... ph

From time@ice.com  Ukn Aug  6 00:08:53 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA07062; Fri, 6 Aug 93 00:08:50 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA06591; Thu, 5 Aug 93 21:05:39 -0700
Received: by heifetz.msen.com (/\==/\ Smail3.1.22.1 #22.11)
	id <m0oOIsr-000Hd0C@heifetz.msen.com>; Thu, 5 Aug 93 23:54 EDT
Received: by tbomb.ice.com (uA-1.7b6); Thu, 5 Aug 93 20:00:51 EST
From: time@ice.com (Tim Endres)
To: hydro@Hawg.Stanford.EDU
Subject: Re: hydroponic questions
Date: Thu, 5 Aug 93 20:00:51 EST
Organization: ICE Engineering, Inc.
Reply-To: time@ice.com (Tim Endres)
Message-Id: <1CE00001.8e5rji@tbomb.ice.com>
X-Mailer: uAccess - Macintosh Release: 1.7b6
Status: RO
X-Status: 


In Regards to your letter <9308022000.AA16964@Hawg.Stanford.EDU>:
> Well, I'm going to take a random guess at this, which may or may not
> be right.  Not all plants like to be submerged in water 24 hours a
> day.  That's why many hydro systems fill up the aggregate and then let
> it drain back out.  Likewise, that's why it's good to soak your soil
> and then let it drain completely.  When you soak a medium, all the
> spaces fill with water.  As the water drains, air is drawn down into
> the soil.  You then have water clinging to soil/agg particles, with
> air in between the particles.  This is the environment many plants
> like to grow in.  My guess if this ventilation system is for supplying
> roots with air under water.  It has nothing to do with cooling.

This is another reason why the Thin Film Nutrient system is so
good in my opinion. The nature of the "mat", which is continually
"pulling" solution down past the roots, gives excellent and 
natural aeration while the solution is flowing. Plus, since the
solution is rarely more than 1/8" deep, and the roots exist
in a large open area, there is a great deal of exposure to air
for the roots.


tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)

USENET - a slow moving self parody... ph

From schuch@bopper2.phx.mcd.mot.com  Ukn Aug  6 08:48:58 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA18614; Fri, 6 Aug 93 08:48:56 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA26102; Fri, 6 Aug 93 05:46:38 -0700
Received: by bopper2.phx.mcd.mot.com (5.61/MCDMAIL IR04 [07/23/90 15:51]/1.34.bopper2)
	id AA11343; Fri, 6 Aug 93 05:39:28 -0700
From: schuch@bopper2.phx.mcd.mot.com (John Schuch)
Message-Id: <9308061239.AA11343@bopper2.phx.mcd.mot.com>
Subject: Thin Film Nutrient System?
To: time@ice.com
Date: Fri, 6 Aug 93 5:39:14 MST
Cc: hydro@Hawg.Stanford.EDU
In-Reply-To: <1CE00001.8e5rji@tbomb.ice.com>; from "Tim Endres" at Aug 5, 93 8:00 pm
X-Mailer: ELM [version 2.2 PL10]
Status: RO
X-Status: 

> 
> This is another reason why the Thin Film Nutrient system is so
> good in my opinion. The nature of the "mat", which is continually
> "pulling" solution down past the roots, gives excellent and 
> natural aeration while the solution is flowing. Plus, since the
> solution is rarely more than 1/8" deep, and the roots exist
> in a large open area, there is a great deal of exposure to air
> for the roots.
> 
> tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)
> 

Could you give me a simple explanation of how the Thin Film
system works? It's not in the books I have.

Tnx,
John


-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602)438-3008 - CompuServe: 70733.3330  |
+--------------------------------------------------------------------------+

From schuch@bopper2.phx.mcd.mot.com  Ukn Aug  6 08:59:55 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA18951; Fri, 6 Aug 93 08:59:53 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA26124; Fri, 6 Aug 93 05:56:53 -0700
Received: by bopper2.phx.mcd.mot.com (5.61/MCDMAIL IR04 [07/23/90 15:51]/1.34.bopper2)
	id AA11682; Fri, 6 Aug 93 05:48:12 -0700
From: schuch@bopper2.phx.mcd.mot.com (John Schuch)
Message-Id: <9308061248.AA11682@bopper2.phx.mcd.mot.com>
Subject: solution temperature
To: time@ice.com
Date: Fri, 6 Aug 93 5:47:58 MST
Cc: hydro@Hawg.Stanford.EDU
In-Reply-To: <1CE00001.8e5i7d@tbomb.ice.com>; from "Tim Endres" at Aug 5, 93 7:55 pm
X-Mailer: ELM [version 2.2 PL10]
Status: RO
X-Status: 

> Nothing can do more for your plants than *strong* (I mean high capacity)
> ventilation. Ventilation is more critical than many other things.
> ......
> down through a deep ditch that they dug and buried. Others have run
> it through cool water. In Phoenix, you may not have many options.

I plan on placing evaporative cooling pads at one end and fairly large
exhaust blowers at the other. That's about the best that can be done
here short of refrigeration.

> 
> Also, under hot conditions, you need to be very concerned about the
> temperature of the nutrient solution. Too hot, and the plants will
> not be able to exchange nutrients well at the roots. 

I had not considered that. How hot is "too hot?"

>
> Thus, I would
> set up some system that allows you to have some control over the
> nutrient solution's temperature. Even ice cubes added occasionally
> can give you pretty good control.
> 

I imagine I could use the cold water reservoir from the evaporative
cooling system to control the solution temperature. I'll have to
think about that.

tnx
John


-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602)438-3008 - CompuServe: 70733.3330  |
+--------------------------------------------------------------------------+

From time@ice.com  Ukn Aug  6 13:22:18 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA02026; Fri, 6 Aug 93 13:22:14 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA26596; Fri, 6 Aug 93 10:18:09 -0700
Received: by heifetz.msen.com (/\==/\ Smail3.1.22.1 #22.11)
	id <m0oOVE6-000HdCC@heifetz.msen.com>; Fri, 6 Aug 93 13:05 EDT
Received: by tbomb.ice.com (uA-1.7b6); Fri, 6 Aug 93 12:48:37 EST
From: time@ice.com (Tim Endres)
To: schuch@bopper2.phx.mcd.mot.com
Subject: Re: Thin Film Nutrient System?
Date: Fri, 6 Aug 93 12:48:37 EST
Cc: hydro@Hawg.Stanford.EDU
Organization: ICE Engineering, Inc.
Reply-To: time@ice.com (Tim Endres)
Message-Id: <1CE00001.8g0t4w@tbomb.ice.com>
X-Mailer: uAccess - Macintosh Release: 1.7b6
Status: RO
X-Status: 


In Regards to your letter <9308061239.AA11343@bopper2.phx.mcd.mot.com>:
> Could you give me a simple explanation of how the Thin Film
> system works? It's not in the books I have.

Thin film is pretty simple.

Nutrient is "pulled" over the roots via capillary and gravity action
in a very thin film (about 1/8 inch). The nutrient flows continually.

The home brew system that I have seen consists of 4 inch pvc tubes.
Then concrete was poored down them to create a flat surface about
a third of diameter. The flat surface is critical, since most of the
nutrient "spreads out" via capillary action. Then they placed a "mat"
that they purchased at the nearest fabric store down on top of the
concrete flat part. Then the tubes are set at an incline of about
one inch per 5 feet. Nutrient is pumped from the resevoir to the
"top" of the tubes and allowed to "trickle" down the matting across
the roots of the plants and back into the resevoir. The trickle rate
is precisely one quart per minute. The capillary action of the matting
pulls the nutrient out so that you don't get a tiny stream that only
covers a small part of the roots. Thus, there is about a 2.5" area
of dark air around the roots. The plants grow up out of 2 inch holes
cut into the PVC tubing and are started in rockwool and placed into
the tubes when they are big enough. The rockwool is the one inch cubes
so they fit and the small holes help support the stem.

The system I use is commercial, from SunCore Systems (1 503 281 6401
ask for Chuck). It is plastic triangular tubes with flat bottoms (this
avoids the problem of flattening round pvc tubing). It has a mat
that is about 6 inches wide, which helps a lot and has more capacity
than the 4 inch pvc, which only provides about a 2.5 inch flat mat.
The nutrient is pumped up the tubes via a small (3/4 inch) pvc tube
running up inside the larger triangular tube. I love this system and
it has produced results that I have never seen with any other hydro
system.

Finally, with Thin Film IT IS VERY CRITICAL to have the correct nutrient.
SunCore provides the best I have used, and I have had other supposedly
hyodro nutrients "burn" my plants. The problem stems from UREA based
nitrogen used in most, since there are no micro organisms in the tubes
as in soil to break down the urea. Otherwise the urea will burn the
roots and ultimately kill the plants, or severely restrict their growth.


tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)

USENET - a slow moving self parody... ph

From time@ice.com  Ukn Aug  6 13:24:35 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA02105; Fri, 6 Aug 93 13:24:32 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA26609; Fri, 6 Aug 93 10:20:43 -0700
Received: by heifetz.msen.com (/\==/\ Smail3.1.22.1 #22.11)
	id <m0oOVEA-000HdGC@heifetz.msen.com>; Fri, 6 Aug 93 13:05 EDT
Received: by tbomb.ice.com (uA-1.7b6); Fri, 6 Aug 93 12:52:26 EST
From: time@ice.com (Tim Endres)
To: schuch@bopper2.phx.mcd.mot.com
Subject: Re: solution temperature
Date: Fri, 6 Aug 93 12:52:26 EST
Cc: hydro@Hawg.Stanford.EDU
Organization: ICE Engineering, Inc.
Reply-To: time@ice.com (Tim Endres)
Message-Id: <1CE00001.8g1491@tbomb.ice.com>
X-Mailer: uAccess - Macintosh Release: 1.7b6
Status: RO
X-Status: 


In Regards to your letter <9308061248.AA11682@bopper2.phx.mcd.mot.com>:
> > Also, under hot conditions, you need to be very concerned about the
> > temperature of the nutrient solution. Too hot, and the plants will
> > not be able to exchange nutrients well at the roots. 
> 
> I had not considered that. How hot is "too hot?"

If you look hard enough, you will find a couple tables that show the
nutrient exhanges "zones" of plants for both temperature and pH.
I can't point you to one, since I copied mine long ago, and have
had little need to look at it in years.

However, general rule of thumb is that the nutrient has to have the
proper pH and have a temperature in the 62-68 degree range. I do 
believe that pH is a little more important than temperature, but
temp is the easier to control and monitor.

A "dissovled salts" meter is also vital to keep the nutrient concentration
in a good region.


tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)

USENET - a slow moving self parody... ph

From rfrench@cs.stanford.edu  Ukn Aug 19 16:30:56 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA06182; Thu, 19 Aug 93 16:30:50 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA23775; Thu, 19 Aug 93 13:26:22 -0700
Date: Thu, 19 Aug 93 13:26:22 -0700
Message-Id: <9308192026.AA23775@Hawg.Stanford.EDU>
From: "Robert S. French" <rfrench@cs.stanford.edu>
Sender: rfrench@Hawg.Stanford.EDU
To: hydro@hawg
Subject: More on the tomato saga
Status: RO
X-Status: 


Well, my tomatoes are getting a lot worse now.  The lower leaves turn
yellow first, with the yellow appearing between the veins, while the
veins stay green.  My thanks for all the suggestions - I imagine
MirAcid has far too much urea in it.

I just received a large order from Hydrofarm.  Among other things I
got a dissolved solids tester and 12 pounds of crystalline nutrient (no
urea).  I'll try replacing the solution with this new nutrient, and
watch the pH carefully to see if it helps.

How does one use a dissolved solids tester?  Do I make up some
solution, measure it, and then see when it drops too much?  Or is
there some recommended level so that I should add nutrient until the
level is reached?

		Rob

From schuch@bopper2.phx.mcd.mot.com  Ukn Aug 23 15:32:11 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA08756; Mon, 23 Aug 93 15:32:09 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA05739; Mon, 23 Aug 93 12:29:24 -0700
Received: by bopper2.phx.mcd.mot.com (5.61/MCDMAIL IR04 [07/23/90 15:51]/1.34.bopper2)
	id AA24399; Mon, 23 Aug 93 12:21:56 -0700
From: schuch@bopper2.phx.mcd.mot.com (John Schuch)
Message-Id: <9308231921.AA24399@bopper2.phx.mcd.mot.com>
Subject: Opaque vs. Clear Storage Tanks
To: hydro@Hawg.Stanford.EDU
Date: Mon, 23 Aug 93 12:21:43 MST
X-Mailer: ELM [version 2.2 PL10]
Status: RO
X-Status: 


One of the books I've read mentions that the nutrient solution storage
tanks should be opaque. I have found some plastic tanks that would be
ideal for the space I have and are very inexpensive. They are, however,
white and translucent.

Does the solution REALLY need to be kept in the dark?

John

-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602)438-3008 - CompuServe: 70733.3330  |
+--------------------------------------------------------------------------+

From time@ice.com  Ukn Aug 24 11:32:52 1993
Received: from Hawg.Stanford.EDU by SunSITE.unc.edu (4.1/tas-gen/1-30-93)
	id AA25421; Tue, 24 Aug 93 11:32:48 EDT
Received:  by Hawg.Stanford.EDU (5.57/-eef) id AA02472; Tue, 24 Aug 93 08:30:17 -0700
Received: by heifetz.msen.com (/\==/\ Smail3.1.22.1 #22.11)
	id <m0oV04o-000Hd2C@heifetz.msen.com>; Tue, 24 Aug 93 11:14 EDT
Received: by tbomb.ice.com (uA-1.7b6); Tue, 24 Aug 93 10:43:57 EST
From: time@ice.com (Tim Endres)
To: schuch@bopper2.phx.mcd.mot.com
Subject: Re: Opaque vs. Clear Storage Tanks
Date: Tue, 24 Aug 93 10:43:57 EST
Cc: hydro@Hawg.Stanford.EDU
Organization: ICE Engineering, Inc.
Reply-To: time@ice.com (Tim Endres)
Message-Id: <1CE00001.9v8bc5@tbomb.ice.com>
X-Mailer: uAccess - Macintosh Release: 1.7b6
Status: RO
X-Status: 


In Regards to your letter <9308231921.AA24399@bopper2.phx.mcd.mot.com>:
> 
> One of the books I've read mentions that the nutrient solution storage
> tanks should be opaque. I have found some plastic tanks that would be
> ideal for the space I have and are very inexpensive. They are, however,
> white and translucent.
> 
> Does the solution REALLY need to be kept in the dark?
> 
> John
> 
> -- 
> +--------------------------------------------------------------------------+
> | John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
> | N7XVS - schuch@phx.mcd.mot.com - (602)438-3008 - CompuServe: 70733.3330  |
> +--------------------------------------------------------------------------+


The problem is algea growth in the tanks. The opaque tanks prevent
the growth. If you can cover or keep in a dark place to prevent the
algea you should be able to use them


tim endres - time@ice.com  (UUCP: heifetz!tbomb!time)

USENET - a slow moving self parody... ph

