PH Difficult to control

[vanduse1]

Here are my numbers

FC 4.0
CC 0.0
TC 4.0
CAL 310
ALK 95
PH 7.8
CYA 40

I have a SWG 15000 Gallon IG Plaster Pool. My SWG Manual states that 40-60 is the recommended zone for CYA. I have not had a lot of luck raising my ALK. It will raise until I add some Muratic Acid again to lower the PH. I had my PH at 7.2 (Just lowered from 7.8+ over the weekend) on Monday and Tuesday it was back to 7.8 again. I added more acid again last night and will check when I get home. But, PH has been difficult to control. I realize that new plaster and SWG raise PH but does this seem in line? I feel like I add acid everyother day. Perhaps I am micro managing and looking at it too often?

Thanks for all of your help!

[duraleigh]

Van,

I would suggest 4lbs of baking soda. It will raise your Alk up around 115 and perhaps raise your pH again but you can then bring the Acid back down with muriatic. Hopefully your pH will be more controllable.

Your post infers that you are aware the SWG's will most always raise your pH pretty steadily....muriatic will have to be a way of life.....a small price, I think.

[waterbear]

Actually, this sounds pretty normal for new plaster and a SWG. Once your plaster has fully cured it should get a bit better.

[Jeffski]

How often will I need to add acid to my new pool with SWCG? Roughly.

[Poolsean]

It's really all going to depend on what type of surface you have and the quality of the water.
If you have a plaster pool, there's a tendency for the pH to increase almost every day, until the plaster cures. This may take a few months to a year. Again, depending on how much your pH rises, will dictate how much acid you need.
If you have a fiberglass or vinyl pool, the pH rises less and you will have less acid consumption.

Above all, keep your pH in check so that you don't have additional problems down the road.

[vanduse1]

Van,

I would suggest 4lbs of baking soda. It will raise your Alk up around 115 and perhaps raise your pH again but you can then bring the Acid back down with muriatic. Hopefully your pH will be more controllable.

Your post infers that you are aware the SWG's will most always raise your pH pretty steadily....muriatic will have to be a way of life.....a small price, I think.

I added 4lbs. of backing soda last night. I just measured (About 24 hours later) and I am only measuring TA of 100. My PH is off the chart again. I added some acid again (about 30% - 40% of a gallon). I seem to add about a gallon every 2 or three days. That is the only way I can keep the PH in line.

Do you think I may need more backing soda since I am only at 100 now? Perhaps it will take another day or two to register. Maybe since I am adding so much acid it is keeping my TA from raising??

Any help would be apprecaited.

Dan

[duraleigh]

I added 4lbs. of backing soda last night. I just measured (About 24 hours later) and I am only measuring TA of 100. My PH is off the chart again. I added some acid again (about 30% - 40% of a gallon). I seem to add about a gallon every 2 or three days. That is the only way I can keep the PH in line.

Do you think I may need more backing soda since I am only at 100 now? Perhaps it will take another day or two to register. Maybe since I am adding so much acid it is keeping my TA from raising??

Any help would be apprecaited.

Dan

Hi, Dan,

Yes, Alk will move up and down somewhat as you move your pH. That's ok. Testing after 24 hours of dosing is adequate.

Alk of 100 is fine for now. Go ahead and keep your pH in line as your priority and then adjust your Alk as you need. Maybe let it get back down to 80 or so and then bring it back up around 100 but keep you pH in the range you have been all along.

Rising pH in a new pool is pretty well a given as is rising pH with an SWG. To my knowledge you cannot put in too much acid or baking soda...it's far more important to keep your parameter in the ranges suggested.

I think you'll start to see some reduction in your acid consumption soon but I do not have a good feel for when that will occur.

[Poolsean]

WHOA..why are you raising your alkalinity to begin with? 95 - 100 ppm is just fine. Heck, when you look at your saturation index, you have perfectly balanced water. Why change it?