I'm having red cyano bacteria, came out of no where.

been looking for ways to beat it and get rid of it but can't find a clear answer. For now i did chemiclean.

Any advice of how to get rid of it? I know improving flow, but anything else?

parameters:
ALK: 8.5
Cal: 400
Mag: 1350
Phos: .03
Nitrate: 05