Really Need Help With Cyano

Oh and how much carbon should I be running in a 20 gallon long reef?

 

I agree with this. I would also add that these power heads slow down if not cleaned regularly. You might not be getting the flow you think you are if you haven't cleaned it in a while. The reduction is so gradual that you don't always notice the drop off.

 

Approximately none. If you really like it, throw about a cup in a good bag and stick it in your overflow... If you have tangs in a 20 reef, you have more problems than a little lateral line disease.

 

Tangs?

 

Where did the tangs come from?

Also to the op: it is feeding on something but once it grows and consumes it all then it will not grow anymore. Manual removal will do this.
But if you have a sand bed that is releasing built up nutrients into the water column then the cyano will not stop for a good year yet... No matter how many detrimental biological filter chemicals you use.

 

No, no. That was a joke. Given the size of the tank, I assumed there were no tangs. If the assumption was wrong, he would have way more problems than any caused by carbon. Sorry for the confusion.