decreasing alkalinity without decreasing pH

Jul 28, 2007
Please help me. My pool is somewhat cloudy. i got a test kit it said my alkalinity was high (270ppm; but the pH was ideal 7.6). went to pool store and they told be to slug the pool. I added 2 1/4 cups of ph down ( in 1 gallon water slurry) to a 1250 gallon above ground pool. It dropped the alkalinity to 120ppm- Great but now the pH was below 6.8. I had to raise the pH back up with pHUP (sodium carbonate) and know the pH is 7.6 but the alkalinity it back up to 270ppm. I basically am going in circles. We are on well water, i added calcium stabiliszer and chlorine shock but that is the only thing that has every been in the pool. It is also usually covered. How can you decrease alkalinity without decreasing pH or once you decrease alkalintity how do you raise pH without raising alkalinity again? Can you help me???? someohow suggested airating but ia ma not sure how to do this either. thanks


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Welcome to TFP!

You want to lower the PH to 7.0-7.2 with acid, then aerate the pool to bring the PH back up. Repeat this process as many times as needed to get your TA down to where you want it. Adding acid lowers both PH and TA. Aeration raises PH while leaving TA alone.

You can aerate in many different ways, waterfall, spa jets, fountain, pointing the return up towards the surface so it breaks the surface and causes turbulence, having a bunch of kids swimming in the pool, rain, etc.