We had an algae problem a week ago. took a water sample to the local pool store on 6/6 after adding 2 gals of liquid chlorine:
FC 2; TA 2; CYA 150; TA 120 pH 7.5 phosphates 2000; dissolved solids 3000
Added 6# of shock over 36 hours. Chlorine not holding. but Algae getting under control with some added brushing.
Drained a foot of water and added back hose water 3 x over 3 nights.
Today's water sample results:
FC .5; TA .5; CH 220; CYA 30; pH 7.4; Phosphates 2500; dissolved solids 1900
backwashed filter today and ready to add m. acid, wait til sundown and add shock. Pool store recommend Phos Free, but after visiting your site I see it's a money maker for the store.
Any other recommendations?
Location: Phx Arizona, 19,000 gals, IG Plaster blt-1999 pump 1.5 hp Nautilus FNS 48 DE filter