Pure Pool Supplies, Inc.
PO Box 16596
Quick answers to the most common questions
PO Box 16596
"pH" refers to the acidity/basicity level of your pool water. The reason it’s important is that unless your pool is within a certain pH range, your chlorine can’t chemically interact with the bacteria and algae it’s supposed to kill. Most pool owners don’t realize how important the pH level is, and how much extra it can cost to maintain a pool without the proper pH level. For example at a pH of 8, only 20% of the chlorine in your pool will actively kill pathogens and contaminants. As well, a swimming pool with improper pH can be damaged, surfaces can be etched or corroded, liners can become brittle, and equipment will have a much shorter lifespan.
There are many things that can lower your swimming pool water pH. Your local water source might have a low pH to begin with. If you continually find yourself fighting low pH, then this might be the cause. You may have added too much pH reducer in an attempt to lower the swimming pool pH after testing. “Trichlor” chlorine tablets have a low pH, roughly 2.8 – 3.0. With consistent use, it can reduce your swimming pools pH level. Shocking the pool will lower the pH, whether you use chlorine-based shock like calcium hypochlorite (cal-hypo), or non-chlorine shock (potassium monosperulfate). Rain picks up acidic elements in the air, which also lowers the pH. Large pool gatherings (high bather loads) introduce contaminates naturally through perspiration, saliva, bodily oils, urine and fecal matter. These contaminates can all lower the pH.
If your swimming pool pH is low, you are putting your pool surface and equipment at risk of damage. Here are typical problems pools with low pH can experience. Metal surfaces such as light fixtures, railings, ladders, screws, pool cover components, pool heater components, and any metal in your pump and filter are at risk for corrosion. Concrete, plaster gunite or shotcrete, and fiberglass pools can all be damaged in their own way, such as etching, pitting, and delaminating. Vinyl-lined pools can become brittle and eventually crack and tear. Stone, decorative tiling, coping, and masonry surfaces can also dissolve and deteriorate in acidic low pH pool water.
Your local water source may have a higher pH, as municipalities tend to avoid water that is too acidic. So, adding more water to the pool can potentially raise the pH. As well, if you use a salt generator (commonly referred to as a having Saltwater Pool) these tend to raise the pH as part of their chlorinating process. The most common cause for high pH is simply adding to much pH Up in the last dose, or adding other chemicals with pH increasing additives.
If your swimming pool pH is high, swimmers might complain about the water irritating their eyes and causing their skin to feel itchy or sticky. High pH can cause a hazy, murky, or cloudy pool. For sanitization, any chlorine added is much less effective at higher pH levels than pH-balanced pools. The extra cost of adding more chlorine is much more expensive than maintaining the proper pH levels. Over time, high pH can cause water to scale, resulting in filters and fittings plugging, reduced water circulation, an increase in water and a large strain on your pool equipment. This higher water shorten the life of your pump motor, heater, chlorinator, and filters.