Cyanobacteria problem

[Zachary Hart]

Hello. I have had cyanobacteria in my 13.5 gallon Evo for many months now and it's starting to get on my nerves. Ive looked up to see the primary causes, but can't seem to identify any in my tank. At the moment I have 1 clownfish, 1 cleaner shrimp, 1 red legged hermit crab, 3 cerith snails and two trochus snails. I do a 20% water change weekly and use rodi water. I swapped out the sponge filter that came with the tank for a diy one made which uses filter floss. The floss is changed twice weekly. I also have the recommended protein skimmer which is doing a good job at producing skimate. For the light I have opted for the ai prime. I also have another powerhead to keep the water moving so there are no dead spots. Please can anyone tell me what I'm doing wrong and why the cyanobacteria keeps coming back. Thanks

[MrObscura]

What are your no3 and po4 readings? 

 

Anyway, usually elevated nutrients are blamed or cyano but I had them when mine got low, and then hey bottomed out resulting in dinos.  So, be careful. As long as nutrients aren't cray high it might be best to try and ride out the cyano, especially if it's a young tank without much biodiversity. 

[Donny41]

Do you have more than 1 powerhead? The way you rock structure is I would think you would need more than 1 to get decent flow around the whole tank, especially if it's a non controllable one.

[Zachary Hart]

I bought a hydor koralia nano 900 powerhead and the tank has the return pump with split outlet nozzles which also provides flow

[Zachary Hart]

Phosphate is 0.03

Nitrate is reading 0