How to keep pool water PH around 7.2

Costas > DownUnder

Bronze Supporter
Dec 17, 2017
Adelaide | Australia
What sort of pool - Fibreglass, Concrete etc ? Is it a new or old pool?

Also what are you using to measure the PH?

Generally you would use Hydrochloric acid to drop the PH but also keeping an eye on Total Alkalinity.

You can simply use Baking Soda from your supermarket to increase TA (PH buffer) if required.

You can use the Pool Math Calculator - Plug in your values and it will work out the acid quantity required to drop the PH as required. PoolMath

May I suggest you fill out your signature with your pool details so others can chime in and assist easily...:goodjob:


TFP Guide
Bronze Supporter
Jun 27, 2012
Edmond OK
This is a common problem with saltwater chlorine generators. If your total alkalinity isn't too high, there's not a lot you can do other than to periodically add muriatic acid to bring the pH down. I have to add a gallon every week or two.

Anything that stirs the water will raise your pH as well, so if you have any water features like fountains or waterfalls, turning them off will help. And keep your returns aimed down enough that they don't stir the water surface.


TFP Expert
Mar 3, 2011
A pH of 7.8 tends to work better than 7.2. There's really no reason to try to maintain the pH at 7.2.

If you really want to keep the pH at 7.2 without affecting the TA, you can set up a carbon dioxide injection system.

It works the reverse of aeration. Instead of removing carbon dioxide and raising the pH, you add carbon dioxide to lower the pH.

The problem is that the carbon dioxide comes back out like a soda going flat.

So, you end up spending a lot of money on carbon dioxide for no good reason.