I have 4 similar setups (non-planted tank) on a 4 tier rack
The top 2 tiers are doing great, but the bottom 2 always have Cyanobacteria issues after 2-3 weeks.
I tried 100% total reset, ie new tub, new filter media etc etc, yet the Cyanobacteria still came back after 3-4 weeks (took slightly longer thou)
I suspect the main cause is the indirect sunlight (heat and lighting), I use cardboard to block out 70% of the sunlight, but doesn't solve the issue
Any idea how to solve this weird issue?
Posted by KimKimPlease
1 Comment
I don’t think light contributes to cyanobacteria. Some people recommend a light blockout for a few days after treatment, but it’s not an algae it’s a bacteria. You can try treating it with peroxide. There’s also specialty products just for cyano. Some people recommend using an antibiotic.
I had it in a couple of tanks and a pond. I suspect it was coming from the rainwater tank. I tried peroxide in the tank, but it didn’t get it out of the substrate completely. I used tetracyclene and it worked a treat for me. It was really cheap, too. Now I also treat my water with peroxide before I add it to the tank. No more problems.
From what I read, the cause of cyanobacteria isn’t widely agreed upon. However, excess phosphate can trigger it. So if you’ve got a phosphate test you could test those tanks.
Be aware that some treatments can crash your cycle.
ETA – barley straw is often used in large ponds and dams to treat cyano. I used some in the pond and it helped. All you need to do is float it in the water.