dude, i think maybe if you put some muscle/clam/shelfish/snails things in there the water will be cleaner/more healthy for alpha, without removing nutrients that plants want. not sure, but i've had various fish and plant tanks and seems to work...
And before anyone says anything... yes I know the water is starting to get cloudy... I want to know how bad and how fast things get ... just bear with me... but let's keep in mind that the fish's job is to fertilize the water, so if I change the water at the first sign of cloudiness, I might as well get rid of the fish...