Help with Phosphate and Cyano!!

[sundog101]

Ok, here's the the deal, I'm a beginner and have a biocube 29 and I'm having trouble controlling phosphate and Cyano bacteria. Basically I have Cyano all over my sand bed and a lot of my rocks and I don't really know what to do. I think that it's being caused by high phosphates which are at 0.16. I also need some help with lowing my phosphates. I'm using RO/DI water and have a protein skimmer. I don't think I'm over feeding (just in case I've cut back).I've been using phosguard, but it has not helped much. I do not have a reactor though. The tank is not in direct sunlight. About a month ago I did 3 days darkness which killed all the Cyano but it came right back in about a week. Surprisingly I don't have much algea. I do have a tuxedo urchin though, and he keeps the rocks pretty algea free.
About my tank: 29 gallon biocube with 25 lbs live rock has been set up for about 3 months. I have a clownfish pair, royal gramma, and orange stripe goby. I have a banded coral shrimp, pistol shrimp, blue tuxedo urchin, and a brittle star. I have a few corals as well which seem to be doing really good despite the Cyano outbreak. Parameters: ammonia-0, nitrite-0, nitrate-2, phosphate-0.16, KH-10dKH, calcium-420, salinity-1.024 SG.
I really don't know what else to do besides adding a gfo Reactor which might be little tricky in a biocube. Any help would be appreciated. Thanks!!

 

[pickupman66]

So....you can rid your tank of cyano with Chemiclean. This is a bandaid solution and if you dont address the phosphates, it will return or somethign else will take its place to consume the phosphates. You can remove phosphates with GFO, a Fuge or water changes. I use Lanthanum Chloride to drop mine down should I feel it is too high. Please read up on it before doing it.

 

[Randy Holmes-Farley Verified Community Expert]

The Phosguard likely needs to be changed more often and use more of it, or use GFO to bind the phosphate. I'd look to drop the phosphate and hope that helps with the cyano.

Other methods, such as organic carbon dosing or growing acroalgae or an ATS may be helpful in reducing the nutrients the cyano is consuming.

 

[cginter]

I'm using hc GFO and still having problems with cyano. I don't get it.

 

[Randy Holmes-Farley Verified Community Expert]

Have you measured phosphate?

Maybe you are not using enough GFO, or are not changing it frequently enough.

FWIW, it isn't magic, it just helps to get phosphate very low to cut it off before the cyano can use it.