Bob Lowry’s Start-Up Science for Every Pool Surface

A pool surface only gets one first impression, and that impression happens during startup. The choices you make in the first days decide whether the finish cures clean or inherits permanent flaws. We walk through the core methods—barrel, traditional, and hot acid—and, more importantly, the decision tree behind them. Source water chemistry sets the tone, especially calcium hardness and alkalinity, while metals like copper and iron lurk as silent stain makers. The fastest way to lose a finish is guessing. The fastest way to protect it is to test, document, and treat the water before it touches the plaster. That mindset shapes every recommendation below.

Startup method matters because surfaces differ. Barrel startups were designed for low calcium and low alkalinity water, using either sodium bicarbonate (OnBalance) to lift alkalinity or calcium chloride (Orenda) to raise hardness as the pool fills. The aim is simple: load the water with enough calcium and buffering to reduce or prevent plaster dust. Exposed aggregate and quartz finishes often push techs toward an acid or “hot” startup to strip cream and reveal texture, but that approach is risky in untrained hands. A traditional startup—NPC, a retailer guide, or Bob Lowry’s “Boring” method—prioritizes measured steps: daily testing, controlled additions, and written records. That structure helps you balance toward a near‑zero saturation index while preventing aggressive water from attacking fresh plaster.

The most important day is day one. Test the fill water for calcium hardness, total alkalinity, pH, copper, and iron before you start. If calcium is under 150 ppm, plan to add calcium chloride as soon as the pool is full to reach at least that threshold, because the Langelier saturation calculations assume calcium saturation. Metals demand even more care. Potable water can legally carry enough copper or iron to stain brand‑new plaster. If combined copper and iron exceed about 0.4 ppm, prioritize removal. A hose‑end pre‑filter that strips metals is the cleanest solution because it prevents metals from entering the system. If metals are already in the pool, use a metal‑removal media in the skimmer and only use a sequestering agent as a temporary shield, understanding it does not remove metals and degrades under sun and chlorine.

Plaster dust is chemistry made visible. Lowering pH slightly helps dissolve dust into ionic calcium rather than letting it precipitate as scale. That does not mean driving pH to the floor; keep it near 7.0 to 7.2 to stay effective without risking surface burn. Good filtration helps too: cartridges outperform sand for capturing fine dust. If you must recover a neglected startup, add a clarifier polymer rather than alum to bind fines without creating a flocking mess, and move quickly to balanced targets so the surface stops dissolving or scaling. Document every test and dose. An app or printable log builds a defensible record and a repeatable process.

Fresh plaster is fragile. Do not stop the fill once it starts, or you will etch a permanent ring at the waterline. Pad the hose end so it cannot scar the surface while the pool fills. Keep wheels and robotics off the finish for weeks; vacuum heads with wheels can track the surface. Keep pets and eager swimmers out until the water is balanced and the finish has time to hydrate and cure. If a builder fills and walks away, bring in a pro to take control fast: confirm metals, set calcium to 150–200 ppm initially, hold pH low‑normal, and begin systematic brushing and filtration. For stains and heavy scale, pair a removal product with actual metal removal so the water can redissolve what’s on the wall and carry it to the filter media.

Great startups are boring by design: test daily, adjust deliberately, and think ahead. Use a pre‑filter when metals are present, hit calcium targets early, manage pH to keep dust soluble, and keep careful records. Those habits turn chaotic first weeks into predictable outcomes. The payoff is a smooth cure, stable water, and a surface that looks the way the builder promised. The cost of discipline is small compared with resurfacing or living with stains that never should have formed.