Whats diatoms peoplepeople? I've been leaving the light on in the tank for good lengths of time, and I've got quite a lot of 'brown' growing on the rocks, and on the glass. Is this algae? Any good for mbunas to graze on? Not actually seen them picking at the rocks. My aim would be to make this their main source of food, like in the wild, and just supplement/treat them with flake etc...
Any suggestions?
Cheers