Algaecide doesn't help. If Algae 60 is poly...<xxx> 60% and nothing else, it will drive your fc to 0, which is OK. However, other algaecides do more harm than good.

What you need is lots and lots of chlorine. Get your FC level to 12 and keep it there, checking 3x/day. Your pH is low so you should put in Borax to raise it. But for now, Bleach/liquid Chlorine and Borax are ALL you should put in. Don't worry about anything else till you break the back of the algae.

Carl