May 2022 HOA Living Magazine

The Silent Battle - Pool Chemistry

By Mark Feldstein

There is a very quiet, yet persistent battle waging beneath the calm surface of a swimming pool. From the moment a new pool finish is applied to a pool or spa and filled with water, the battle begins.

We have all heard the expression, “Water seeks its own level”. Well, that also applies to water chemistry. Water naturally seeks equilibrium or ‘its own level’, If, for example, the water being used to fill the pool has low Calcium Hardness levels, unless the pool maintenance technician remedies this by adding Calcium Chloride during the fill to proper levels, a minimum of 200 PPM, water will attempt to find this balance by leeching calcium out of the pool finish. This practice will help prevent the leeching process from occurring.

This must be combined with being careful not to cause over-stabilization of chlorine by over-using Trichlor or Dichlor tabs (cyanuric acid). Commercial pools regularly use these tabs and overuse suppresses alkalinity. It also slows down Chlorine’s ability to kill pathogens and algae. Over-stabilization, highly conditioned water, causing low alkalinity makes water aggressive which can cause etching and irreparably damage the pool surface.

To prevent this, water chemistry must be carefully monitored, maintained and adjusted keeping in mind that the amount of pool usage and weather conditions can impact water chemistry. This is why what worked last month may not work this month – actual water testing is necessary. Chemicals should never be blindly added to the pool because “that’s how much I added last week”.

Draining and refilling pools when Total Dissolved Solids (TDS) gets close to 2,000 PPM also helps to eliminate build-up.

Learn five factors that play a major role in swimming pool water chemistry, and how you can control common issues in this area.

Swimming Pool Water Chemistry: pH Balance

pH is the major factor you should keep balanced when maintaining your swimming pool water chemistry. pH refers to the level of acidity in your water and comes from the use of chemicals to keep it balanced and free from contaminants and algae growth. You want your pH to remain between 7.4 to 7.6 at all times to avoid burning eyes and to allow for free chlorine use.

Swimming Pool Alkalinity

Closely connected to pH, the alkalinity is the amount of base, or hydrogen ions, in your water. It also refers to the ability of your water to contain and reduce the loss of hydrogen. Keeping your alkalinity balanced helps to keep your pH levels optimal when additional acids or bases are introduced to the water. You want your pool’s alkalinity to be between 80 to 120 parts per million (PPM).

Pool Water Calcium Hardness Levels

Your pool has dissolved calcium salts in its water. These can increase from the oils and salts on people’s skin, from debris that falls into your pool, and from the chemical reactions that form from maintaining your water balance. You want to keep these levels between 200 and 400 ppm. If the calcium level is too low, it can create pitting in the plaster, while high amounts of calcium make the water cloudy and can result in scaling.

TDS (Total Dissolved Solids) in Your Swimming Pool

When a pool has been in use for a long time, things like suntan lotion, chlorides, dirt, debris, algaecides, and other contaminants can be introduced into the water from leaves, tree bark, dirt, skin chemistry, and other factors. TDS can’t be avoided, but it should be kept between 300 and 1,800 ppm.

Pool Chlorine Levels

Chlorine is, for many people, a vital part of keeping the chemistry in their water properly balanced. Too much chlorine, and you’ll end up with burning in the eyes and a strong odor. Too little, and the pool’s alkalinity and pH will be out of control, leading to things like cloudy water and algae growth. Ideal chlorine levels should be at 0.2ppm or less, and free chlorine should be in the range of 1 to 3 pm.

Mark Feldstein is the CFO and Marketing Director for Gardner Outdoor and Pool Remodeling, which has been serving the Southern California area since 1969. As one of the States and the exclusive SoCal referral partner of Leslie’s Pool Supplies, Gardner Remodeling is the premier pool contractor in San Diego County, LA County, Orange County, and Coachella Valley. You can contact our Indio office at 760-342-9756. Mark can be reached by email at markf@gardnerremodel.com.