Siphon out as much as you can, do a water change and increase the flow within your tank so you have no 'dead' areas.Snails will help to a degree, but you need to fix the cause of the cyano or it will continue to reoccur.
Quarantine the sick fish or fishes and treat with copper.Especially tangs.2 weeks or so should do it.A ich breakout is real bad and can kill everything in there real quick.
my friend adds sugar to his sump.. dunno how much he adds but I know it cured all his problems with red allgee if you want you can message him on here
questionmarc is his user name I think he adds a teaspoon once a day and he has 150 gallon
as for ick if you can qt the fish, one of the best livestock i have bought is my cleaner shrimp, they help alot with the problem, but wont solve the problem, water change, flow for the cyano, also do you use a ro\di to filter tap water ?