Maintaining the water chemistry in your pool is important for swimmer’s comfort and safety, but did you know that it can also affect your pool heater? Pool heaters work by flowing water through a heat exchanger. Many newer models are less susceptible to problems caused by an imbalance in water chemistry, but older models have copper parts that can be damaged by pool acidity.
Acidity and your heater
Your pool becomes acidic when the PH and alkaline levels are low. In early stages of damage, the acid interacts with the copper to leach minerals and metals into your pool. You may start to see some discoloration on the pool liner or grates and corrosion on pool equipment. You may notice yellow or rust colored stains at first; later a violet discoloration indicates heavy mineral deposits in the pool water. A damaged heater is also likely to leak. If it gets to this stage, you’ll probably have to replace your pool heater.
What if the heater is off?
Even if you aren’t using your heater much, all of your pool water passes through the housing between the pump and the pool. That means water chemistry damage can occur even during the summer when you don’t turn the heater on for months. As a result, whether you’re using the pool or using the pool heater, if there’s water in the pool, always make sure the chemistry is balanced.
Factors that affect pool water chemistry
- Free Chlorine – If you have way too much free chlorine in your pool, you know it. There will be a strong smell, your eyes will burn, and the color will bleach out of swim suits. There’s no industry standard for the level of free chlorine, but there are reliable DPD (diethyl-p-phenylene diamine) test kits on the market that determine whether your water is in an acceptable range.
- Chloramine – Total chloramine residual should be balanced in the system, never greater than 0.5 ppm over the amount of free chlorine.
- PH Factor – While it rarely affects swimmers, the pH balance can corrode mechanical equipment, stain pool surfaces, and change the interaction of other chemicals in the water. We recommend maintaining pH balance ranging from 7.4 to 7.6.
- Alkalinity and Calcium Hardness – These factors are major contributors to scale deposits and corrosive action, and factor heavily in proper care of pool heaters and other equipment. It’s best to maintain water alkalinity between 50 and 125 ppm and calcium hardness should remain between 200 and 500 ppm.
Other factors that may affect water chemistry are temperatures, circulation, and even swimmers and the products, organisms, and urine they bring into the water. It’s not difficult to test and maintain chemically balanced pool water and prolong the life your pool heater, it just takes diligence, a little know-how, and a well-stocked testing kit.