Total Alkalinity Too High..pH Too Low..Swimming Pool..

by Virginia

Total Alkalinity Too High..pH Too Low..Swimming Pool..

by Virginia
(Texas)

We have not been able to get our vinyl lined, 20,000 gal., in-ground pool water to clear up this Summer. The total alkalinity is too high (around 130ppm). The pH is too low - 6.8ppm.

How can I lower the alkalinity without lowering the pH at the same time? Also, 12 hours after chlorine is added, there is no free chlorine indicated by the chlorine test.

We changed the sand in the sand filter hoping it would help clear the cloudiness.

We have added clarifier with no result.

Help!!

Thanks for your question Virginia

I would encourage you to get, if you already don't have one, a Reagent FAS-DPD K-2006 pool water test kit. It's the best one on the market.

Water Testing Kit

You're not completely out of range for your total alkalinity and pool pH level. Just some simple adjustments are needed.

You lower both alkalinity (TA) and pH level with muriatic acid.

It's basically this for the TA: With the pump off, pour the acid in the deep end of the pool. Very gently sweep the bottom of the pool to break up any "hot spots" of acid.

Allow this to sit for about 2 - 3 hours, turn the pump back on and allow the pool water to circulate for one full turn-over, about 10 - 12 hours, then re-test the TA.

This will lower the TA without much happening to the pH level.

To

raise the pool pH level, you can use sodium bicarbonate. It's just normal baking soda, or 20 Mule Team Borax works as well.

With the pump on, pour the bicarb. around the perimeter of the pool, starting in the deep-end. Allow for one full turn-over of the water, then re-test.

Once you get the TA at 80ppm - 120pm and the pH between 7.6 - 7.8, you'll be fine.

Concerning your pool chlorine level, normally your pool will lose chlorine because there's a lack of cyanuric acid (CYA).

What you're using right now is an unstabilized form of pool chlorine, probably liquid or granules. CYA is the stabilizer for the chlorine. You need to get some CYA into your system.

Get it between 30ppm - 50ppm using the above link. Your Reagent K-2006 test kit will have a test for CYA and it's very easy to take this reading.

You might get residual dirt and sand back into the pool because of the recent sand change. This is normal and will decrease in time as the sand settles and gets a little more debris in it.

Your swimming pool sand filter needs a little bit of pressure to work correctly.

If sand does come back through the returns, just vacuum it up.

You're pretty close to having a great pool. Just a few easy corrections should do it. It will take a little time and patience, but it will be worth it.

Good luck and have a great Summer

Robert