P.f.dreams - LaMotte manufactures an inexpensive fairly accurate chemcial test kit for dissolved oxygen; abt $40.00. Kits are availabe from numerous suppliers of aquaculture and environmental products. Common one is Aquatic Eco-Systems (
www.aquaticeco.com ). LaMotte may have a web site.
Tests involve collecing a sample that is not agitated and collected with minimum exposure to the air. Exposing water to the air even air bubbles tends to add a little oxygen and error to the sample.
The test takes about 5 to 10 minutes and involves 3 chemical additions/reactions. Step 1, Fix or stabilize the oxygen in the sample that creates a wiskey colored flocculant. Step 2, Dissolve the flocculant. Step three, titrate the sample (add drops to create a color change). Amount of titrant indicates how much DO was in the water.
