I have an algae bloom that is going out of control in a pond I originally fertilized with cottonseed meal too. I will never again fertilize with cottonseed meal. It's all alfalfa meal from now on. Initially the cottonseed meal turned the water brown and Bill Cody believes the fertilization is catching up with me.

You do know why your PH is pretty stable through the dial cycle right? It's due to your high alkalinity buffering any PH changes. I have the same situation in my ponds.

Is your groundwater so high in nitrates due to lots of agriculture in your area? Is it possible you ground was tilled originally or worse yet was a hog lot?

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.