Spa pH Balancing


n a spa, pH is very important. Low pH can damage surfaces and equipment and can cause eye and skin irritation, while high pH can cause scale build-up and cloudy water. Proper pH balance is also necessary for the sanitiser to work the most efficiently, but it is often difficult to maintain pH in the ideal 7.4 – 7.6 range.

Test the pH twice a week and adjust as needed.

High pH:

Many things about a spa cause the pH to stay or appear high. The pH is naturally raised by warm water (obviously common in spas), other products, foreign substances and bather load (proportionately high in spas). Aeration is also a culprit – it releases carbon dioxide from the water, which in turn reduces the amount of carbonic acid present in the spa. This causes pH to increase. To lessen the effects of pH drift, add chemical products with the aeration off. Use SpaGuard Lo’N’Slo to lower pH.

CAUTION: A common mistake that is made with pH in spas is to diagnose it as high when it is actually low. In brominated spas, the brominating product reacts with the phenol red reagent to form bromophenol blue and make the pH reading look purple. This discolouration is exaggerated when the pH is already low. Use up to 5 drops of chlorine neutraliser to make sure that you are getting accurate pH readings when testing with phenol red. Alternatively, use a calibrated pH electrode and meter.

Low pH:

Low pH is usually attributable to low total alkalinity and/or use of Brominating Tablets. The latter can cause the pH and the total alkalinity to drift down rapidly. If this product is being used, check pH frequently to avoid equipment damage. As indicated above, use up to 5 drops of chlorine neutraliser to make sure that you are getting an accurate pH reading if you are testing with phenol red. Use SpaGuard Balance Pak 200 to raise pH.

pH and Perfect Balance:

Perfect Balance helps regulate pH. Spa pH adjusters can still be used with this product, but are not usually necessary. Perfect Balance employs a phosphate buffer which helps lock the pH in place and eliminate some of the normal fluctuation. Apply Perfect Balance according to ALEX instructions. It will cloud the water as it causes the calcium to precipitate. When Perfect Balance is used, pH still must still be checked and may need to be adjusted occasionally. Follow ALEX instructions for pH adjustment when using Perfect Balance. For more information, see Water Balancing with Perfect Balance.