Over filtering

[adamsfour]

Hello fellow reefers
I am having a small breakout of Cyanobacteria. It’s certainly manageable. I know I can remove it with a treatment of chemiclean but it comes back. I have been told I am over filtering as my nitrates and phosphate are very low. I am hesitant to remove/change my filter setup for fear it will cause other issues. Presently I use a pellet reactor and phosban reactor. I am sure other have had similar experience and solved it. Looking for recommendations the breakout is primarily on the gravel in a low flow area

 

[Miami Reef]

Cyano is a fickle beast. There isn’t an established consensus (from what I’m aware) on how to eradicate it short of chemiclean or peroxide.

Some people will say higher flow helps prevent cyano from settling.

I think I’ve heard more reports of cyano issues from people using bio pellet reactors.

@taricha Do you have a guideline for cyano treatment?

 

[ryanjohn1]

I have some on a rock that is being blasted by nero5 at max speed. I see it disappearing when no3 and po4 are better balanced

 

[Mikeltee]

All you should need is a skimmer. GFO is for phosphate bound rock. If your Phosphates are high once your rock is in check, you are doing something wrong.

 

[Randy Holmes-Farley Verified Community Expert]

I don’t think over filtering is a contributor to cyano.

 

[taricha]

@taricha Do you have a guideline for cyano treatment?

To me there are several distinct scenarios for cyano growth. So the effective responses that a hobbyist can do don't always match up from one tank to the next.
One scenario is if you stress or kill algae, cyano slime frequently covers it.

Another one of the most common ones - probably the case in this thread - is accumulation of organics and low flow allows for high local available nutrients that cyano mat communities can exploit. Also it allows low O2 & low pH at the sand surface that can let additional goodies be liberated from the sand - PO4 and Fe (beyond the organics that settle there).

So vacuuming and higher flow are often helpful to remove that set of conditions

Since it's rare to be able to drive cyano growth with simply the nutrients in reef tank water, for local cyano mats I'm generally in favor of repeated vacuuming, letting it burn out local nutrient stores, and changing flow/feeding so food isn't accumulating there.
If you do chemical killing, I'd still vacuum local trouble spots.