Best way to lower pH without lowering TA

[Nojodas67]

Hello,

I have a SWG and my pH seems to creep up every week. TA level is right around 80. I was adding muriatic acid to control the pH rise, but after a while the TA level dropped to 40. After a few increment additions of baking soda, finally got it back up to around 80. pH is creeping up again.

Is there a better way to control pH without messing up the TA level? I know pH can be manually raised by installing a water feature or turning the jets towards the surface, but I need a method that will do the opposite.

Thanks in advance.

 

[Donldson]

Why are you raising the TA back to 80 when that is causing the trouble? 40 is a bit too low but you can definitely keep it around 50-60 to help with that.

 

[JoyfulNoise]

Lower your TA and consider adding borates to your pool water. Since this is an indoor pool, you should not need to run the SWG much given the lack of UV. Long term you should consider oversizing the SWG and converting to a variable speed pump as that will allow you to dial back the SWG output a lot and avoid any additional aeration it might cause. Also, being an indoor pool (and fairly small sized), can you cover the pool with a bubble cover? Keeping the water covered will not only save you on heat loss and room humidity but it will also keep the pH more stable as it will stop the outgassing of CO2 (because you have high TA). The outgassing of CO2 from the water is what is driving your pH rise. A few years back I used a bubble cover for a few weeks. When the cover was on, my pH was incredibly stable (it barely moved) as opposed to when the pool is uncovered and I had to add acid every 7-10 days.

 

[Nojodas67]

I must have notifications turned off because I just checked and you guys answered my question right away and I had no idea.

Wow...your answers are right spot on and actually makes sense. The reason why I was trying to keep the TA at 80 is because my Taylor k-2006 kit says TA must be between 80-120. But if you think I can keep it at around 50-60 then I'll do that.

I actually do keep a cover on the pool between Sept and May, as we do not spend much time at the lake house during that time, during those months, I run the pump on low speed for 1 hr at noon and 1 hr at midnight just to keep the water to circulate and so the SWG at 10% so it makes a little chlorine. During summer months, the pump runs for about 6-8 hrs/day with SWG at 10-20% depending on usage.

I ran across a couple of posts that briefly recommended the use of borates, but I have to do some more reading on it for instructions on how to do it, where to buy, what to buy, etc. A link ot a couple of posts would help me a lot.

Also, I have well water; so do I need to be concerned with the amount of iron or calcium in the water? When I first purchased this house 3.5 years ago, there was A LOT of build-up on the walls below the water line. The prior owner, did NOT maintain the pool at all and nobody ever swam in it since he had no kids, and his wife never visited the lakehouse; he said he kept the pool covered all year round, ran the pump an hour a day, never brushed the walls or did any maintenance. When I purchased the property, the fiberglass walls were light blue above the water line, but whitish/grey below the water line; I thought that was the color. I later found out that the white/grey was years of build up on the blue pool walls. At first, when I just rubbed my hand on the walls below the water line, a white powder would come off the walls and dissolve in the water and turned the water like skim milk in the area where I rubbed just with my fingers. I spent a good 3-4 weeks scrubbing the heck out of the walls for a few hours per day with scotch brite pads, working in small sections at a time. During this time, I would have to remove and wash down the cartridge filter every day; the rinse water would be white like milk.


Now, there isn't any more powder coming off the walls on it's own, unless I scrub really hard, but the walls below the water line are not quite the same color, as above the water line.

Right now the fill water for the pool bypasses the house water softener. I read an article that states that if I switch to soft water, that the soft water will latch to the calcium build up on the walls and dissolve it into the water, where it can be removed by the cartridge filter. Is that true?

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This is a seat, which is below the water line. I scrubbed a small section that is now light blue.