Bill,
Good call, I did not mean to make phytoplankton sound like one type of plant (but did)
last year I was called out on a fish kill. the pond was very small maybe 1/10th of an acre. it was dug out for irrigation and was very deep. the pond owner was sold an aerator by a salesman that lead him to believe many non-truths. It was a diffuser type aerator. this was the wrong pond for that type of aerator as there was much more water under the thromocline than above. the aerator broke down the stratification as advertized but did not provide enough oxygen to keep fish alive. We turned off the aerator, oxygen levels went back up naturally and fish were happy once again.
