Cyano :(

[Northvan]

We feel your pain. We've been fighting it for a year. We've done chemiclean (temporey improvement, but comes back), 3 days lights out with tank wrapped (no improvement at all), just finished a bottle of cyano clean with coral snow (1 month, $120, actually seems to have gotten worse).
We haven't yet tried erythromycin (antibacterial), not sure how to dose it.
Tank is almost no fun anymore.
Cyano sucketh .

[martinmcnally]

My cyano is completely gone now however it wasnt straightforward with the chemiclean.

I did the first clean as per the manual, basically everything off with an airstone running for 2 days. However after the 2 days I wasn't satisfied so I went another day. Removing the chemiclean seemed easy, 1 water change plus carbon and the skimmer was running again within a few hours.

However the cyano wasn't gone just reduced. I waited a week or 2 and did another 3 day treatment. This time was vastly different. The cyano was completely gone after 3 days. However removing it from the water was much more difficult. It took 3 water changes, new carbon and allowing the skimmer to overflow for around 10 days before it returned to normal and started skimming again.

Much harder on the second run than I thought but its gone and the chemiclean appeared to have no affect on coral or fish.