By Eric Knight

Four Pillar Concepts to Own

The vast majority of swimming pool chemistry problems boil down to just four common denominators, which we call The Four Pillars. Proactive pool care is about preventing issues, so each of our four pillars has an easy-to-follow action step. If you do any of the four action steps, pool care becomes easier…but if you do all of them, pool chemistry issues will become very rare.

The first pillar is LSI Balance and Calcium Management.

This is about water balance, as measured by the Langelier Saturation Index (LSI). This index gauges the calcium carbonate (CaCO3) saturation of your water, with 0.00 being perfect. As long as your water is within the -0.30 to +0.30 range, your water is in balance. There are six factors to keep track of, which means more in-depth testing. But if you look at it the other way, if you’re not testing all six factors, you only know half the information you need to balance your water chemistry. The six factors are pH, carbonate alkalinity, calcium hardness, water temperature, total dissolved solids (including salt), and cyanuric acid.

The action step is to keep your water LSI balanced, which is easy to keep track of using the free Orenda app’s LSI and chemical dosing calculator. Doing this action step can prevent carbonate scale, etching, most plaster discolorations and damage, fading vinyl liners, and/or deteriorating fiberglass.

The second pillar is Non-living Organic Management.

While chlorine is an outstanding disinfectant, it is a comparatively weak oxidizer. Yet more than 90% of the contaminants in pools are non-living oxidants, like bather waste. Many of these oxidants, like sunscreen or cosmetics, are complex molecules that take a lot of chlorine to oxidize out of the water. Failure to manage these organics will lead to a much higher chlorine demand than is necessary, cloudy water, oils and scum lines on tile, and fouled filters. Chlorine is not designed to get these oils and organics out of the pool, but we can complement chlorine with things that are much more capable against these non-living organics.

The action step is to complement chlorine with enzymes and/or secondary systems like Ozone, UV, or hyper-dissolved oxygen (HDO). Enzymes rapidly break down carbon-based organic waste and are a much more efficient way to handle bather oils and sunscreen. Doing this action step of complementing chlorine will yield cleaner, clearer water, improved chlorine efficiency, and a more pleasant look and feel to the water.

The third pillar is Phosphate Removal.

Phosphates are constantly being introduced to water, and nowadays most water treatment facilities put phosphates in the tap water too. They are a problem because of the problems they contribute to, and because chlorine cannot remove phosphates. Because chlorine cannot oxidize phosphates, they simply accumulate until eventually the pool becomes eutrophied, which will need to be remedied. The action step is to keep phosphate levels below 500 ppb. According to the research, keeping phosphates below 500 ppb can reduce the minimum free chlorine to CYA ratio (FC:CYA), which goes a long way to improving chlorine efficiency. Fortunately, phosphate removal is safe and easy to do on an as-needed or regular basis.

The fourth pillar is minimal cyanuric acid (CYA).

The fourth pillar is minimal cyanuric acid (CYA). CYA controls many aspects of pool chemistry, from chlorine strength (% HOCl) to chlorine speed (contact time [CT]). CYA also negatively impacts the LSI, making water more aggressive. Stabilization is important because CYA protects chlorine from sunlight degradation…but too much CYA leads to overstabilization, which has no benefits, only drawbacks. High CYA requires a proportionally higher level of free chlorine in order to keep disinfection and oxidation working in your water. Because overstabilization is such a prevalent problem, it is our fourth pillar of proactive pool care. The action step is to keep CYA to a minimum. The ideal is 30 ppm, and we recommend a maximum of 50 ppm. You can go higher, but you will also need to keep the free chlorine level higher along with it to maintain the free chlorine to CYA ratio (FC:CYA). If you don’t have 7.5% of your CYA ppm in free chlorine, your pool cannot keep up with algae growth, and you are likely to have an outbreak. For example, if you have 100 ppm CYA, you need 7.5 ppm free chlorine as a baseline. But as mentioned in our third pillar, if you keep phosphates below 500 ppb, that number can be lower than 7.5%, perhaps by half (but we are awaiting research to know for sure).


Orenda has a philosophy of minimalism, which requires being proactive with pool care. Almost any water chemistry issue we have come across can be prevented by following these four simple action steps. For more information, we have an entire free online educational program called Orenda Academy™ for you. We also have the more advanced Orenda Academy: Four Pillars™ program online, which is also free. In those programs we go more in depth on these concepts, and we hope to help you optimize your pool chemistry and prevent issues.

Eric Knight

Orenda Technologies
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