Saltwater Pool PH Havoc

[jagercrow]

Hi everyone! Hoping to be pointed in the right direction. 1 year old pool/spa with Intellichor Saltwater Generator. Can’t keep the PH below 8.0. Even pool person is totally lost. They don’t put liquid chlorine only acid(it was my understanding since the generator produces the chlorine not to add extra liquid on top). Chlorine PPM reads at 3500-3750. This is causing absolute havoc on my plaster especially in the spa. Anyone seen this before?

[waterbear]

First, your chlorine ppm is  NOT 3500 - 3750. That would be your salt reading.  The reason your pH is constantly high is because your total alkalinity is too high. First step is to post a full set of test results NOT done with strips since strips are useless for balancing water. FC, CC, pH, TA, CH, and CYA. If memory serves me the Intellechlor like the CYA between 50 and 100 ppm. 

As far as adding liquid chlorine (or any other form if chlorine forcthat natter) there is no reason why you can't if you FC is low, you need to shock because of persistent CC greater than .5 ppm or you have an algae outbreak because of ignoring your water testing and water parameters.

Read these: 

https://www.poolspaforum.com/forum/index.php?/topic/52523-some-truths-about-ph-and-ta/

https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/

Post a full set of test result and we can take it from there.

[jagercrow]

Thanks for the response Waterbear! Oh wow lol. Yes you’re right that’s the salt level not chlorine. Here’s the readings my pool person gave today. Granted I have no clue what method they use to obtain the readings:

POOL SERVICE INFO

 

READINGS

7 ppm  free chlorine

7 ppm  total chlorine

8.2  pH

40 ppm  total alkalinity

[waterbear]

NOT a full set of test results. Need to know calcium hardness (NOT total hardness, which is what strips test) and CYA (cyanuric acid, chlorine stabilizer).

Also I see a possible red flag with apparent high FC, high pH and low TA. It is possible that your FC is much higher and the test (which I assume is a DPD test) is suffering a partial bleachout. High sanitizer levels can bleach out the DPD test and cause it to read much lower than it is and will give a false high pH reading and a false low TA reading and this needs to be ruled out by either testing total chlorine with an OTO test or using a FAS-DPD titration test for chlorine.

This is a year old pool so the plaster is not fully cured and it looks like there are calcium deposits on the finish. A new pool requires a LOT of acid until the plaster is fully cured and this can take up to two years. The calcium hardness test is important because if you fill water is very hard this will promote scaling.

I would also suggest getting a Taylor K-2006 test kit and doing your own water testing.

https://www.taylortechnologies.com/en/page/231/k-2006-complete-kit-with-fas-dpd

This kit will test all needed parameter except salt level and uses the FAS-DPD testing method , which does not bleach out and is a drop count test with a definite color change from pink to colorless. IT will also test much higher FC levels than a DPD test without bleachout. You can get it from online sources such as Amazon and many online pool/spa retailers., (No, I don't work for nor am I affiliated with Taylor Water Technologies in any way. They just have the best water testing products in my opinion and experience.)

Good test results are the basis of proper water balancing and based on what you have said and the pictures you posted you have water balance issues.

 

[saunaguy]

That’s definitely classic salt pool pH drift. Saltwater generators naturally raise the pH over time because of the way they split water molecules (producing sodium hydroxide. If you’re not regularly dosing with muriatic acid or using a pH controller, it’s super common for it to creep up past 8.0. Also, 3500–3750 ppm is your salt level, not chlorine for chlorine you want to check free chlorine in ppm, not salt content. You might want to check total alkalinity too if that’s high, it can make the pH harder to control. Lowering TA a bit can help stabilize things. Also consider borates they can buffer the pH swing and help protect your plaster.