I always have a diatom out break every time I over dose. It gets so bad it covers the leaves in thick diatoms and then the anubis start to die because the leafs cant receive any light. Then I have to pull all my anubis and wash every leaf by hand. It is very time consuming. The java moss is impossible to clean so it just struggles. Maybe you have too much nutrients and not enough plants so the algae just feeds off the excess? How many hours do you keep your lights on? Try keeping the lights on for no more than 7;30hrs. Forget the pleco, all they do is poop. I'd buy otos from aquabid and have them shipped next day. Otos are the best with diatoms.