CH levels and CSI increasing

[hcrossing]

My latest testing numbers show my CH and CSI numbers increasing. I'm using the TF Pro test kit to perform the tests.

Once in a while, when we are planning to be close to the local Leslie's Pool, I also compare the results with their numbers and typically we are somewhat in line with each other.

However, today their CH number is 1500 vs my 425.

I've noticed lately that my SWG cell has calcium build up on it and I've had to run it through a muriatic acid wash twice in the last 6 weeks.

Thoughts on what may be happening here and what to do? Thanks.

 

[Rocket J Squirrel]

The quickest & simplest way to lower your CSI is to lower your pH. You also have high TA, so adding muriatic acid should help with both. Your CH looks reasonable to me. Get your pH down to the low 7's.

 

[Texas Splash]

We almost always trust your testing before the pool store. No telling how/why they achieved such a high number. That's why we avoid them at all costs. As Rocket noted, your CSI (and potential for scale) is attributable not only to the CH, but also pH, TA, and water temp. PH has the most immediate and dramatic impact, so be sure to keep that controlled. For the next week or two, I would make it a point to lower the pH to about 7.0-7.2, let it rise, then knock it down again. Each time you do that it will help to lower the elevated TA as well.

 

[pjt]

I'm using the TF Pro test kit to perform the tests.

Please add your test kit to your signature.

when we are planning to be close to the local Leslie's Pool, I also compare the results with their numbers

Don't. Your test kit accuracy and precision is superior. Pool store results add confusion.

I've had to run it through a muriatic acid wash twice in the last 6 weeks.

Acid cleaning should be a last resort since it shortens the cell life.

Thoughts on what may be happening here and what to do?

You need to consistently add MA to control your pH and TA. CH of 425 is easy to manage if you control the other aspects of your water chemistry.