So recently I had a pretty bad outbreak of cyano I've been monitoring all my params, nitrates are at 0 and phosphates are now between 0-.25, I've done 2 20% water changes over the past week and it seems to be getting worse. I have a koralia right on the bed of where this is at and have also taken my lights down to 8 hours. Can anybody point me in the direction of taking care of this without chemicals?

I use RO and my kalk and calcium are right on as we'll......