Been there done that man! Haven't had red hair algae but cyano is common mistake we do as beginners. Phosphates do cause algae issues and I love and bide by natural so water changes or macro/plants to help control the nitrates, and all those things so a mangrove garden or refugium is king!

Some of the things I think you may have jump guns with like reactors but that's just me. Keep it simple and move on.

I don't know what 30ppt is...? I personally prefer the 1.024 for salinity. .025 is nice too. I have a friend who has his low at about .021 cuz he says his coral grow faster that way lol. To each there own HAHAHHAHA!

Lighting is usually how I look at it is 2-3watts per gallon.