High ph

[dombey]

Hi guys,

I drained my pool a few weeks back and ever since the ph has been out of control - I add muriatic acid to bring down to 7.2, and like 48 hours later, it's up around 8.2.

My TA is 120 and I've read on here to try bringing it down around 60 and see if that helps.

Here's my issue: I've been adding acid to keep the ph in check but the TA isn't going down with it, so presumably I need to add acid faster and aerate the heck out of it to get the ph up as fast as possible. But I don't want my pool to be rocking a 3.0 ph for any period of time either... so how low can i go on ph during this process without causing damage?

 

[coloeb]

How long ago was it plastered? dont go lower than 7.2 on ph to start. Plaster curing will elevate ph levels. Do you have any water features like a water fall or fountian. Do you have spa jets turned on that would be airating the water? This would cause the ph to rise as well, although like you said with the MA addition would lower TA. Rain or excessive water makeup? Have you added borates or other chemicals during this time? Posting a full set of readings would help determine water balance issues.

 

[JasonLion]

As the TA level comes down, it will take longer for the PH to go up.

Your TA is going down, just not quickly enough to show up obviously in the test. If you keep at it, you will get there. Adding more aeration can speed up the process, but isn't required.

You can bring the PH down a little lower each time, targeting a PH of 7.0 is very reasonable once you are familiar with the whole process. Lowering PH further will speed everything up a little. If you do aim for a lower PH, you need to take extra care to be sure you don't add too much acid and overshoot.

 

[dombey]

How long ago was it plastered? dont go lower than 7.2 on ph to start. Plaster curing will elevate ph levels. Do you have any water features like a water fall or fountian. Do you have spa jets turned on that would be airating the water? This would cause the ph to rise as well, although like you said with the MA addition would lower TA. Rain or excessive water makeup? Have you added borates or other chemicals during this time? Posting a full set of readings would help determine water balance issues.

It was plastered years ago. No features, I have aerators I can use but usually don't. I live in phoenix so it doesn't rain. No additional chemicals.

I don't believe I have any water balance issues. As of this morning, TA=120, FC=5, CYA=50, CH=210, ph=8.2.

 

[chem geek]

Check the TA of the fill water. When there is evaporation and refill, whatever is in the fill water gets added to the pool, including TA and CH. You might need to do the TA lowering procedure to get the TA lower faster, but if your fill water is high in TA then that can be a challenge long-term.