I've been watching the progression of my tank that was formerly green. It has been fascinating to watch. Once the rotifers took over they exhausted nearly all the algae and the tank was brown with millions of rotifers. Suddenly a few hydra appeared, then hundreds as they were well fed from the rotifers and reproduced like crazy. Within a few days the rotifers were gone and they hydra starved. Suddenly dead hydra were floating around and the snails were feasting on them. Today there was no sign of hydra or rotifers, and the water is once again turning green. Looks like the cycle is poised to start again.

I put about a dozen male Endlers Live bearers in the tank to suppress the rotifers. Hopefully I can break the cycle and maintain the tank green for my moina. Moina do OK and the sweet potato/ yeast mix, but nothing like they do on green water.