Basic question about PH balance levels

Someone told me that ph balances only lower when you put in muriatic acid so no matter what, the ph reading will either be the same or higher unless muriatic acid is added. Doesn't the ph balance fluctuate with chlorine levels or how much usage the pool is getting too?

I'm asking because where I am we test the pool/spa twice a day and at times the ph balance is a lower reading than the previous one and no muriatic acid was added. I was told this was impossible because the ph balance never goes lower unless muriatic acid is added.

I'm new to the forum so I apologize if this question is in the wrong place.

Hi, Melissa,

The pH of pool water generally is ideal between 7.2 - 7.8

Most folks on this forum use muriatic acid to adjust it lower and 20 Mule Team Borax to raise it.

Many other factors have an influence on it as well....up or down.

One of the most common things that lower it in residential pools is the 3" tabs or pucks that are used for chlorination. However, using plain bleach as a source of Cl will slowly raise pH.

Acidic rainfall can frequently lower it as well.

So, yes depending on the type of Cl used, ph can drift up or down. Pool usage is probably a pretty marginal factor.

Also the pH test itself can suffer interferance from high chlorine levels. Some pH tests in better kits are more immune to this than some of the cheaper ones. If you just shocked your pool the pH will probably read very high but this is a false reading. Only check and ajust the pH when your chlorine levels are below 10 ppm to be sure.

I rely on the BBB method solely. My CYA is around 30, and I have to add a little Borax at least once a week to keep my PH up. This is without a single drop of rain since we've had the pool up...Oh, we did have some snow in late April. :) I have always wondered why because it seems to be the opposite of everyone else, but it's true.

Shelley

Quote:

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Originally Posted by duraleigh

Hi, Melissa,

However, using plain bleach as a source of Cl will slowly raise pH.

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Using bleach does not always raise your ph. I use bleach only, but never have had it raise my ph. I do occasionally, however, have to add some Borax to raise it - usually after a lot of rain.

Thanks for the responses! Lots of information all over the site. Hope you all have a great day!