What Causes High pH and Alkalinity in a Swimming Pool?

The main reason pH is high for a swimming pool is high alkalinity.

To avoid high alkalinity, add Alkalinity Increaser slowly while measuring its level.  If alkalinity goes above 120ppm, your pH will certainly rise.

The second cause of high pH in a swimming pool is using Calcium Hypochlorite (powder chlorine) pool shock to sanitize the pool water.  Cal hypo comes with high pH and Calcium level and will greatly increase pH in the pool if you don’t take prior measures to balance your pH.

Also, abnormal rise in TA might be caused by the water source.  It could be that your pool fillwater is already high in alkalinity and will increase your TA once it mixes with more Alkalinity Increaser you are using.  Test your water source first for alkalinity and use a different source if it does have high TA.  You would need to use too much dry acid more often to lower both pH and TA in your swimming pool.

Getting the perfect balance of pH and alkalinity is a little tricky since acid will lower both but not at the same rate.

Call  Ohana Pool & Spa for a water testing and the correct chemicals to get your Maui swimming pool in perfect running order.

Our services include water testing, chemicals, repairs and maintenance of your existing Maui swimming pool, plaster and resurfacing and weekly Maui swimming pool cleaning and inspection.