My friend bought a house with a fiberglass pool, 12' x 25', 10000 gal., with 4 laminar deck jets, a spa, a 460 sq ft cartridge filter and a variable speed pump. Also has a 250 btu gas heater. There is also a tablet feeder so you can guess what one problem is.
I went to check his water today as there was some algae on the walls. The results were: 0 fc, 0 cc, 0tc, 5 ph (water in test was yellow so must be lower than 6.8) 0 ta (water was pink without adding any 009 solution) ch 120, cya 100 +. The water is clear and approx 80 deg. I brushed the walls and added cl to get to 13 ppm. I know that a water drain would be good to reduce the cya but with the drought conditions maybe he could manage the way it is. I believe the first thing would be to get the ph in line and according to pool math he needs to add 11 pounds of borax to get the ph to 7.3, since we really don't know the ph prob add half that amount and retest so we don't go over. If he were to just run the laminar jets could that raise the ph enough? After that 5 pound of baking soda to get the ta up to approx 50. At that point the minimum cl level is 7 and target is 12.
Just wanted to check and see if I'm on the right track. With my pool the ph always rises and the ta has always needed to be lower so all I ever have needed is muratic acid.