By salinity up I'd say at least 1.024, alk 9-11 and pH consistently above 8.2. I don't like to take alk any higher as it starts to be risky for calcium. 8.4, 8.6 are really good pH numbers to shoot for, and not, despite what you might believe, terribly high. 8.0 - 8.2 is a low pH for real seawater.
You won't be able to get your pH that high by using an alk buffer, you'll need to drip/add kalk.
These will get your cyano under control, and will also minimise green hair algae growth that will otherwise replace it BUT YOU MUST GET HTE NUTRIENTS OUT - DOING THIS AND NOT TUNING YOUR SKIMMER AND SO ON IS A WASTE OF TIME - otherwise when you let the pH go down again all your problems will reoccur