Runaway PH

[HRR8998]

My pool is new and just had the swg installed and I am taking care of it myself. The pool is about 12,000 gallons, has 3 18” waterfalls which I run all the time (10hrs/ day) and the swg is a Chlorsync cs30 which I have set at 35%. My stats are 5ppm chlorine, 90 TA, 40 cya, 300 calcium hardness and a runaway ph. I get it to 7.4-7.6 and in 48 hours it’s back to 8.2. I’m using sodium bisulfate to lower the PH.

Is this normal? Am I releasing too much co2 through the waterfalls? Should I run the pump less?

 

[Flying Tivo]

I’m using sodium bisulfate to lower the PH.

You should re-read the SWG instructions, Sulphites are not good for your SWG. Use Muriatic acid. Your water features are making your PH rise fast. Only use the waterfalls when you are in the pool. You can also automate acid additions with a stenner pump. Search the Wiki.

 

[jesse-99]

Use MA to lower MA ... you NEED to measure your TA as well with pH, so you know how much MA to use to lower pH. Water features (I have 6, including 2 massive waterfalls) will raise pH constantly. You will may need to limit your use of the waterfalls to prevent co2 outgasing so much (you can compare pH rise (at the SAME TA level) with water features running 10 hours a day versus 2 hours a day, for example) , AND try to keep your TA lower (to buffer the rise of the pH -- I aim for 60-70 on my plaster pool)) . Plan on stocking lots of MA , just like I do... it's the only way if you want to use the features.

 

[jesse-99]

PS, my pool can easily go from pH of 7.2 to 8.2 in 24 hours, so your pool going from 7.6 to 8.2 to 48 hours isn't as bad as mine, lol.

 

[Newdude]

When you adjust the PH, only move it a little to a high 7. Just like any swing, the harder you push, the harder it comes back.

Here is the Wiki page Tivo mentioned. If it's a pool thing, it's probably in there somewhere.

Further Reading

www.troublefreepool.com

 

[HRR8998]

I have read them. It recommends sodium bisulfate, muriatic acid, or sulfuric acid to lower PH.

 

[jesse-99]

FWIW, the reason I personally go for a larger swing (downward) in pH is to also to bring my TA down usually (since my autofill is TA-300) so I have to fight rising TA as well as pH . It works for my pool, but obviously YMMV ...

 

[HRR8998]

Thanks for all the info. I have a 25lb sodium bisulfate pale to return! I will pick up some MA and start using that.

 

[Toxophilite]

With the new plaster, it will be a few months before pH settles down for you. I'm like @jesse-99, my fill water is 265 TA, so my "maintenance" of MA to keep around 7.5 is about 15 ounces every 3-4 days. But, that's only a short-lived time period. After a month or so, I'm up to 100 TA again. A few cycles of taking pH down to low 7's, running spillover more, letting it rise to 8, and then back down and repeat, I'm back at 70 TA and back in the maintenance phase again. I'm going to try much lower, say 50 TA, and see if buys me more time between lowerings. Don't see why it would not. Will be my life with this pool barring going on another water source.

 

[gingrbredman]

Thanks for all the info. I have a 25lb sodium bisulfate pale to return! I will pick up some MA and start using that

Excellent choice!