Could you post a picture of the tank, so we can identify the algae?One of my tanks receives a lot of sun light during the day, and it has quite a lot of (black?) algae.
I just wonder when does it start to become a threat, how much can still be safe for my fishies and plants?
I see, alright, I think it's too much then.When the algae cover the plants so much that it interferes with photosynthesis its a problem.