Regarding Disolved Oxygen Equipment, Here's a DO meter for $195. http://www.aquacave.com/Milwaukee%20Meters.htm . Here's a DO test kit on sale for $29.00. http://www.aquaticeco.com/aquatic1v1/itempg.icl?orderidentifier=ID10504238737884F7C59&eflag=0&iteminfo4=0&itmid=948&passitemid=948 Best Regards, Thomas Giannou http://www.tandjenterprises.com