May make it worse. Cyano seems to take off when the tank gets out of balance. What has changed in that one tank I don't know but something has and it is to the cyano's liking
I got mine when I added some plants that had a little of it on them and it took off really fast. After trying the blackout and other natural methodes I finally used erythromycin and it got rid of it very quickly, and it hasn't returned since.
I have a bit of spare erythromycin if you want to try it. Unlike Alanmin4304, I did not notice any change in my filter bacteria and didn't lose any fish when using it.