Hard to tell what is in the pic. If they are little white worms, they are harmless and multiply with excess food and most visible after a water change. Clean the tank well and cut down on feeding and they should go away. If it wont get eaten, small tetras and bettas will make short work of them
I have numerous tanks and over time that happened only in my tanks holding south americans, so that could make sense. and yep, did a 30% water change and scrubbed the glass on this tank yesterday. Looked nice for 3 hours. The way Africans don't leave uneaten food, and my community tank having several eaters/tetras would certainly explain it. Thanks!
