kate28

I have just google imaged that and yes it looks exactly like Cyanobacteria. I am keeping goldfish but now only have 3 left. They get fed nutrafin flakes every second day and bloodworms once or twice a week. I try to take a bit of water out each fortnight, probably about a third. I don't normally clean the filter but a while ago I took out all the filter wool and started fresh. I used to have heaps of plants but since the algae has taken over most have died and the fish also ate/destroyed some, the few that are left are absolutely covered in it. Should I empty it and completely start again by cycling it? What is the best way to clean the substrate(stones) and everything else?

Hi, I'm new here & hoping someone can help with my problem. My 300 liter cold water tank started getting a vigorous algae problem about 2months ago, its a very dark green algae- almost forest green and looks like a thick layer of moss, mainly on the tank floor but is now covering the plants, wall and filter attachments. I have been siphoning it out regularly which helps for 2-3 days then its covered again. I've tried turning the lights off which has helped a little bit but not much. I added a heater on low which also helped a little but again not enough. I have read algae growth indicates a healthy tank but in the last two months 2 fish have died & also read chemical algae killer is pretty bad for the fish. Is that all correct? I've just bought an 80L temporary tank so I can shut the big one down & start from scratch when the problem is sorted. What is the best way to ensure it wont come back?