Blue green algea

[god8575]

Hey guys new to this board and new to freshwater aquariums. Ok heres the story I have a 55gal aqurium with no fish, waiting for the cycle to happen. By reading the old posts on here I realize that my tank is in a horrible spot because it is it by sunlight not once but twice a day and I run my light constantly. I feel like an idiot. So I wake up in the other morning and have this brown stuff all over the tank which I identify as brown algea now it has progressed to a blue green color. So from the other posts I know I need to black the tank out for 96hrs. But my question is on one of the posts I read that if you dont find out what the algea is feeding off of it will continue to appear is this true and how can I find out and eliminate the problem. Any info would be greatly appreciated. Thanks all

 

[happychem]

Basically a blackout is a really good way to eliminate existing algae and acts like a reset for your tank. You also need to do a 50% water change before and after the blackout.

I'm guessing that you're fishless cycling by the sound of your post. The nitrifying bacteria have no light requirement, so you can easily blackout the tank and continue your ammonia dosings. There's also no need to run your lights at all.

It's true, though, that if you do not correct the problem that the algae will return. However, in a new or cycling tank there's always some instability that allows one form or another of algae to take hold. Also, while fishless cycling, you're providing a lot of food for the algae in the form of ammonia. So just keep the lights off and the problem should correct itself.