Adjusting pH in a Swimming Pool

Grab your test kit and get to work! Today we are going to talk about adjusting the pH of your swimming pool. It is vital to make sure the total alkalinity is correct before we even start on this venture as the two are closely related, siblings if you will. 

We adjust the pH for several reasons. The first being that out of whack pH can cause burning eyes and irritated skin. The second is that the effectiveness of the chlorine to battle all the unwanted contaminants is very dependent on the pH level. The second your pH hits that 8.0 mark, the chlorine is only twenty percent effective and decreases as the pH rises. Chlorine can become overactive if the pH is below 7.0.

Your pH will generally either run high all the time or low all the time depending on the water you are adding to the pool.  Eventually you will get into a weekly routine and probably won’t even have to test the water.

High pH

If your pH is high, you need to add an acid to the water because it is too basic. This can be done in a variety of ways including muriatic acid (liquid hydrochloric acid) or dry acid (sodium bisulphate). Both are extremely dangerous and extra precautions should be taken when handling these. I have burnt holes in my pants on accident with this stuff before.

Before adding any acid, make sure there are no living organisms in the pool because you are about to create an area of high concentration. Make sure the pump is running and grab a plastic bucket to dissolve the dry acid in if you choose this method.

Now it’s time to get that pH in the recommended 7.0-7.8 ranges. Always, always, always add acid to water, never water to acid as this can cause an extreme chemical reaction that could cause serious. Slowly pour the acid around the deep end of the swimming pool. If you have to add more than a couple gallons split it up into a couple of treatments that way you don’t risk damaging the pool and you won’t lower the total alkalinity.

Low pH

This is an easy one as you are just adding an alkali. The most common and easiest way to do this is with soda ash  (sodium carbonate). This comes in a powder for and is much safer than the acid mentioned above.

Disperse the recommended amount around the pool and allow circulating for at least four hours before diving in.

In Conclusion

Adjusting the pH is essential in maintaining the overall chemical balance of the pool and should be done on a weekly basis.