Cyano on certain rocks?

[SalteeDogg]

I been battling with cyano for a while and it has just been driving me crazy! Was wondering why it only grows on certain rocks? Out of the 40-50 rocks in my tank, the cyano only grows on about 6 of them and only them rocks. Am thinking about taking them particular rocks out and replacing them with different one. BUT then I would still have to worry about it on my sand. I can siphon it off my sand before I go to sleep and when I get up the next day, before I even turn the lights on, the cyano ALREADY starts to form back on my sand, IN THE DARK!!! Dont understand how it grows back in the dark but it does..There has got to be a way to conquer the cyano army.

 

[andysgirl8800]

Those particular rocks may be leeching out certain nutrients back into the water that the cyano find favorable. JMO. Do you have anything turning over the sand in your tank?

 

[Bifferwine]

+1 AG. Depending on where the rocks came from, they could have nutrients trapped in them. Also, do these rocks have weaker flow on them than other rocks?

 

[SalteeDogg]

Rocks all have equal flow, they are premium fiji which is the same rock as all my others. I keep taking them out to scrub them but the stuff just keeps coming back.

 

[yote]

Try using a turkey baster and blasting out the holes in the rock.
You may still have detritus trapped in them.That would be enough to fuel a cyano outbreak