I'm new to planted tanks and I wound up dosing a smaller tank with Maracyn to clean up blue green algae on the substrate. Worked great and oddly cleaned up the tank more than I expected so clearly the problem was bigger than I noticed.
I have a 120 gallon tank with the same issue. I want to dose that one next but there are clown loaches in it. Any bad experiences with using Maracyn with a clown loach population?