We recently bought a house with a highly shaded backyard and an onground vinyl pool - 57,000 L. Because I didn't know any better I was using chlorination pucks and was having the local pool store check my water weekly and things started out OK.
Then I noticed when I turned the pump on in the evening brown stuff was jetting out for the first couple of seconds. I assumed it was just dirt and was backwashing the filter... about 3 weeks ago I realized my pool was not getting enough chlorine with the "add a couple of pucks" strategy my pool store was advocating so I decided to switch to BBB which I'd found by this time.
At around the same time stains showed up... small clumps of yellowish-green on the liner. I thought it might be mustard algae so I decided I'd shock the pool.
My levels were
FC = 0
TC = 0
CC = 0.0
PH = 7.5
TA = 150
CH = na
CYA = 35
Temp 75ish
I cranked the FC level up to about 21-22ppm for three days and started brushing regularly. There seemed to be an improvement but the stains were returning a bit each day. So I added 100 ML of polyquat (per the jug) last Wednesday. The pool seemed to improve and the FC was holding steady overnight with no CC. The water looked clearer. There was a noticeable sediment on the bottom of the pool (dead algae?)
I allowed the FC to come back down and I've now since yesterday been working on lowering the TA with muriatic acid. My current levels:
FC = 6
TC = 6
CC = 0.0
PH = 7.5
TA = 120 (this seems odd, I only added 1L of 31.5 % muriatic acid I'm surprised it came down this much?)
CH = na
CYA = 35
Temp 80
The stains seem to be returning to the pool... did I do something wrong here? Should I reshock? Use more polyquat? I'm not sure how to proceed.
Then I noticed when I turned the pump on in the evening brown stuff was jetting out for the first couple of seconds. I assumed it was just dirt and was backwashing the filter... about 3 weeks ago I realized my pool was not getting enough chlorine with the "add a couple of pucks" strategy my pool store was advocating so I decided to switch to BBB which I'd found by this time.
At around the same time stains showed up... small clumps of yellowish-green on the liner. I thought it might be mustard algae so I decided I'd shock the pool.
My levels were
FC = 0
TC = 0
CC = 0.0
PH = 7.5
TA = 150
CH = na
CYA = 35
Temp 75ish
I cranked the FC level up to about 21-22ppm for three days and started brushing regularly. There seemed to be an improvement but the stains were returning a bit each day. So I added 100 ML of polyquat (per the jug) last Wednesday. The pool seemed to improve and the FC was holding steady overnight with no CC. The water looked clearer. There was a noticeable sediment on the bottom of the pool (dead algae?)
I allowed the FC to come back down and I've now since yesterday been working on lowering the TA with muriatic acid. My current levels:
FC = 6
TC = 6
CC = 0.0
PH = 7.5
TA = 120 (this seems odd, I only added 1L of 31.5 % muriatic acid I'm surprised it came down this much?)
CH = na
CYA = 35
Temp 80
The stains seem to be returning to the pool... did I do something wrong here? Should I reshock? Use more polyquat? I'm not sure how to proceed.