Advice for Cyanobacteria


New member
Ive tried siphoning, turkey baster. Ive moved my powerhead to the problem area to increase the flow. Ive reduced the amount of food i am feeding and ive decreased lighting time. What else can I do to fight this pest? Does Chemiclean really work?
I read different things about cyano, some myths and facts alike.
I use to have 2 hermit crabs but they died(back when i had hermits I never really had a cyano problem) Do hermits really eat/help with cyano?

All suggestions are welcome.



New member
Chemiclean will solve your symptom, cyano. Your underlying problem is most likely high phosphates. Solve that and the cyano will go. Do you run gfo? All my cyano disappeared and hasn't come back since I started using it.


Agree with jon99. I never had it (Cyano) until I accidently let my GFO media expire (I had changed to a new type and found it didn't last as long as the prior media). Cyano flared up, I changed the GFO media, vacuumed out the Cyano and it hasn't returned. I altered by media change schedule to suit. Can not comment on Chemiclean as I didn't end up having to use it.


New member
I think another part of the problem is I use to have Feather Caulerpa in my tank and now I no longer do. The Feather Caulerpa was probably eating up the phosphates and now that it isnt the cyano is. Is a GFO the only good way to get rid of phosphates, any other alternatives or thats my only option?


Premium Member
There's several ways to help reduce and control phosphates. GFO is very effective at it and easy to control. I like it to bring levels to maintenance levels. But understand that GFO can become exhausted rapidly and may need changed out frequently at first. There's other methods to rapidly bringing down very high levels but can be dangerous or damaging to your live stock.

For controlling phosphate harvesting algae in some manner is a good long term solution to help maintain lower levels. Carbon dosing(vinegar, vodka, biopellets,etc) is also good at helping to maintain lower levels. Water changes have some effect along with skimming and running GAC. But they maybe indirect or minimal compared to the first two listed.


New member
Personal experience advice if you have a fish only tank.

Pull out each rock and scrub cyano off in a bucket. Replace whatever sand you can.

Then turn off the lights and keep the tank dark as long as possible. Few weeks or even longer The fish only need a little ambient light. If you have to put up a piece of cardboard to block out any sunlight, then do it

I did this in my basement and the rocks are cleaner than when I bought them

So if you can keep the lights out for a long time, do it


New member
The Cyano isnt a huge outbreak, one of my smaller rocks has a little bit on it(I used a toothbrush to get what i could off) Sometimes its hard to see. I have two different kinds from the looks of it. I have a small amount of red(this cyano seems to come and go throughout the months) The one that is becoming the pain in the *** is the Black kind. This is the one in the sandbed and the one rock thats closest to that area of sand. I need to do some more frequent siphoning/water changes and turkey basting to see if that helps along with my reduced lighting/feeding and I have placed a powerhead directly near the problem area. Obviously this fight is not won over night. Any idea/guess as to how long it takes to see real progress?


New member
Chemiclean worked for me for the single outbreak I had. Learned my lesson to increase flow and water change frequency. Haven’t seen it reappear in a year.


New member
It could be the water you are adding into the system are you adding RODI water and when the last time u changed the filters. the next issue could be not doing enough water changes most people recommend 30% every 2 weeks and you could be over feeding the system a good skimmer and live rock and deep sand bed help to minimize these left over organics in the water column.

Pet Detective

New member
Cyano Bacteria is one of the oldest living organisms known to man, in my tank it comes & goes albeit rather infrequently, it tends to develop in the "lower flow" areas of my tank, it really has no adverse affect on any of my inhabitants & the only negative I can see is that it can be aesthetically some peoples eyes. I would never risk a chemical solution to such a natural occurrence that has little to no dire consequences.


Stick Head
I have a minor cyano outbreak in my 25 gal nano. I run GFO and Carbon which I change out weekly and also do a 25% weekly water change. Before doing this I had become lax in my tank maintenance.