Does high KH eliminate Cyanobacteria?

[mandarin man]

I have been battleling the cyano for 3 weeks now, major water changes, increase flow, suck them out as much as I can. Next week, the same amount of Cyano appears on rocks and sand again. It is frustrating.

I have RSM 130 with tunze 9002 skimmer, and vortech 20 pump. I don't think I lack system performance wise.

I have heard and read that high KH from 10-12 will eliminate the cyano. Is this true?

Thanks advance for your help.