Originally Posted by Flux
How long should I do a blackout for and am I doing it to kill the growth of the algae?
OK if you are in need for doing a blackout this is how you should go about it.
First, clean out all visible BGA, prune, vacuum subtrate, and clean out the hoses and filter thoroughly. Then you need to dose Nitrates well. Them cover your tank with large black trashbags. I used packing tape to cover it with the bags, and don't forget to cover your hoses as well. You have to be thorough or it will not work. I even further covered it with a blanket. Obviously turn out all tank lights in the process. Your fish will be fine unfed for 3 days. They willeven get after some of the algae they were getting lazy with...No peeking!
Three days later, take off the plastic,feed your fish, do a 50% change and clean up all of the dead stuff you see, then dose Nitrates again! Give it a full 3 days of blackout, not 3 or 2.5 but 3-4. Once you dose your Nitrates again, resume your dosing as normal, but do not let your Nitrates fall behind again. I hope that helps. Let me know how it goes.
It sounds like you definitely need a blackout by the siphoning volume of the algae.
The purpose is to kill all of the algae <it is really a photosynthetic bacterium> and stop the lifecycle so you can get enough Nitrates going to prevent further regeneration. After the blackout, you should have no sign of it, and you can get ahead of it.