Hanna Instruments HI 96732 Dissolved Oxygen Photometer

In aquaculture, dissolved oxygen is arguably the most important parameter of water quality. Most species require a minimum of 3 mg/L (ppm) DO, 8-10 mg/L (ppm) is preferable. Unlike other gases such as nitrogen, oxygen supersaturation doesn’t usually result in gas bubble disease (“pop-eye”), so high levels generally aren’t an issue.