I had a green pool also, well let me start by saying. When I pulled my winter cover off, I realized my skimmer plate fell off and no plug so I lost water down to the bottom of skimmer in my 18x33 AG. We had 10 " of rain so I pumped it out of my perimeter drain into a 55 gal. barrel then into the pool. I used a slime bag to filter it. got the pool filled and adde metal out because I knew it would turn brown. about a day later after backwashing my DE filter it cleared up. I was reading the forum here and one thread told me to add Polyqaut algecide and keep your PH low. Slowly bring up your Cl each day then adjust PH up. Did that but left solar cover on and had a HUGE Algae bloom. So I added about 5 gallons of Shock 12% and a 1/2 qt or super algaecide. next morning CLEAR. I vacuumed up the dead algae and put 1 bag of Cal.Hyp. in pool . SPARKLING!
Fc=5
tc=1
cc=4
Alk=130
PH=7.3
CYA=30