Quote Originally Posted by derrikm
I have a 10 year old gunite pool, using bleach for past 12 months as a sanitizer and for shock. Ch is approx 550, drain and refill is not am option as my fill water is approx 350. I have been constantly fighting rising Ph. I lower it to 7.2 and in a few days it is in the 8.0 range. TA is 100.

My questions are:
1. Would it benefit me to raise my TA?
2. How high should I go?
3. Will that help to stabilize my Ph?
4. Will it have any positive or negative effects on my Ch?

Thanks in advance for your help. This forum has been a great asset in helping me enjoy my pool and save money at the same time.

DerrikM
1. no
2. 125 is the highest. 100 is fine. Don't go higher.
3. probably not. Something else is driving your ph up
4. Negative. At best no effect, but go too high and your pool will go milky--I'd bet money by 150ppm you'd have cloudy water and at 200ppm I can practically guarantee it.

Some people occasionally find that bleach drives their pH up--it has pH, I believe, of 11. Also, new concrete pools drive up pH as they cure. Has yours been re-plastered or otherwise treated?

Where is your CYA reading? (stabilizer) If it's very low, then Tri-Chlor pucks or Di-Chlor powder would be ideal instead of bleach. Both are very acid. But if CYA is 50 or higher, it would be a mistake.

Draining your water and refilling would lower your CH to 350--that's a good # for a concrete pool--200-400 is recommended, but 550 is too high. If you use Poconos's plastic sheet method you can do a full water replacement with no risk of the pool floating out of the ground. You said it's not an option but I see no reason not to use it...Again, CH=350 is good for your pool, but 550 is too high and MAY be part of your problem.

There are other approaches and others can chip in with them.