Bob Lowry’s Borate Blueprint for a Better Pool

Many pool owners hear about borates and picture a miracle cure that eliminates algae, slashes chlorine use, and makes every maintenance chore vanish. The truth is more useful and more practical: borates, when used correctly, create a more stable water environment that makes chlorine more effective and pH less jumpy. We focus on boric acid at 50 ppm as the sweet spot for most pools, with compelling reasons to adjust for salt water generators. The nuance matters because wrong product choices or poor pre-balance can cloud water, spike alkalinity, or push the LSI too high. When you treat borates as a tool instead of a cure-all, your pool rewards you with clearer water and fewer surprises.

A core concept is chlorine paired with cyanuric acid. Think of CYA as the sunscreen for your sanitizer; too little and sunlight erases your chlorine before it works, too much and chlorine slows to a crawl. A practical rule: maintain free chlorine at about 5 percent of CYA with a hard floor of 2 ppm. That means 40–50 ppm CYA supports 2–4 ppm chlorine under sun. Attempts to run 10–20 ppm CYA often fail because tests are imprecise at the low end and UV loss skyrockets. For salt systems, 70 ppm CYA performs better, cushioning freshly generated chlorine at the cell and near the surface where sunlight can erase 90 percent in two hours. This is not about chasing a number; it is about ensuring every part per million of chlorine does real work.

Borates shine as a pH buffer. They do not stop pH rise; they slow it. Instead of racing to 8.0 in a week, you may see a gentle drift over two, keeping water in a friendlier zone and easing day-to-day care. There is a tradeoff: once pH is high, it can take roughly twice as much acid to push it down compared to a non-borate pool. Smart operators pre-balance pH and alkalinity before dosing borates, then enjoy steadier weeks with fewer urgent adjustments. Users often report silky feel and a visible sparkle—cosmetic perks rooted in more consistent chemistry and reduced microalgae pressure.

Product choice is critical. Boric acid is the clear winner because it barely nudges pH and alkalinity, avoiding harsh corrections. By contrast, sodium tetraborate pentahydrate and decahydrate (borax) can blast pH toward 9 and add roughly 115 ppm to total alkalinity, forcing large acid additions to return to target. That overcorrection can collide with high calcium hardness and high pH to overshoot the Langelier Saturation Index and precipitate calcium, turning water cloudy. The fix is simple: confirm pH, TA, and calcium are in range, then add boric acid to 50 ppm. If you must use borax forms, add calculated acid concurrently to land on target.

How much is enough? Field practice and historical research converge on 50 ppm as the effective preventive level, acting as an algaestat that helps chlorine keep the upper hand. For salt systems, many seasoned techs see better performance at 70 ppm, aligning with the higher CYA recommendation and the way chlorine is generated and exposed to sunlight. Safety guidance and EPA interpretations around 45–50 ppm are often cited; experienced pros weigh that with practical outcomes, staying at or near 50 ppm for standard pools and topping at 70 ppm for SWGs. Remember, more is not always better; it is about matched chemistry across chlorine, CYA, and borates.

Testing borates is a known hurdle. Reliable options include dedicated test strips and select digital spin tests. Because losses happen only with water loss—backwashing, splash-out, leaks, purposeful draining—levels are stable across seasons. That means you usually add a maintenance dose rather than starting from scratch each year. If testing access is limited, careful math works: estimate gallons and use known dose factors to reach your target. For boric acid, about 7.6 ounces per 10,000 gallons raises borates 1 ppm; scale up to 50 ppm and adjust for your pool volume. Track water changes and top off the level as needed to keep the buffer doing its work.

At the end of the day, borates contribute two reliable benefits: they inhibit algae growth and slow pH rise. They do not replace chlorine, they do not eliminate brushing, and they do not erase the need for balanced water. Pair them with the right CYA, maintain a real chlorine residual, and choose boric acid to avoid chemistry whiplash. The reward is water that looks better, feels better, and holds its balance longer, with fewer urgent interventions and a steadier, more predictable maintenance rhythm.