Looking for useful information on how to remove Black Algae and then maintain to keep clear. Problem appeared 4 years ago but was solved by a service, but long since forgotten how. Posting here as new user, although I know similar posts already exist. Thanks.
28,000 gal saltwater pool 8 years old
Use about 120-180 lbs salt / month in summer to keep level about 3,200 ppm after adding depending upon weather and usage
PH 7.3
Chlorine 4.5 - just shocked using Leslies granular high dose chlorine shock
Stabilizer 65 ppm
No Calcium level - but finding out
Added stabilizer and algaecide pre-season - per direction on containers
Pool was "shut down" for 3.1/2 months Dec-Feb - due to ice storm cracking pipes and heater element following pump failure during absence - typical bad timing. Therefore pool was not consistently balanced for almost 4 months.

Here is my current plan;
1. regular (daily is all I can muster) scrubbing w/ss brush
2. Turn up Chlorine to 4+ ?? ppm via adding chlorine in addition to chlorinator boost
3. Add Muriatic Acid - 3 gal
4. Incorporate the "Borax" plan to prevent future algae (of any colour) breakouts.

Do I need to add an algaecide or do something differently or in a different order?

Thanks