Paul Gunder
Paul Gunder is the founder of Rocky Mountain Apps, where he builds calculators and reference tools. Paul had a saltwater pool for a couple of years, years ago.
How the calculators on this site are checked is on the methodology page.
Written by Paul Gunder
Tools
- Cyanuric Acid Calculator: Pool Stabilizer to Add or DrainWork out how much cyanuric acid (stabilizer) to add, or how much water to drain and refill to lower it, with the free chlorine your CYA level calls for.
- Pool Chemical Calculator: Doses in the Right OrderEnter your pool's readings and targets for a dosing list covering chlorine, alkalinity, stabilizer and calcium, in a health department's order of addition.
- Pool Chemical Log: Track Readings and Doses in Your BrowserA free pool chemistry log that keeps readings in this browser, flags them against CDC ranges and the MAHC (a public-pool code), charts trends, exports CSV.
- Pool LSI Calculator: Langelier Saturation Index for Salt PoolsWork out your pool's Langelier Saturation Index from pH, temperature, calcium, alkalinity, CYA and TDS, with salt counted toward TDS and every factor shown.
- Pool pH and Alkalinity CalculatorWork out how much muriatic acid, dry acid, baking soda or soda ash moves total alkalinity to target, and your carbonate alkalinity after the CYA correction.
- Pool Salt Calculator: Pounds and Bags for Your Salt SystemWork out how many pounds and bags of salt to add for a Hayward, Pentair, Jandy or CircuPool salt chlorine generator, from your pool volume and salt reading.
- Pool Shock Calculator: How Much Chlorine to Shock a PoolWork out how much liquid chlorine, cal hypo, dichlor or trichlor raises free chlorine to a shock level, with breakpoint for combined chlorine.
- Pool Volume Calculator: Gallons for Any Pool ShapeWork out how many gallons and liters your pool holds, for rectangle, round, oval and kidney shapes, with one depth or shallow and deep ends averaged.
Guides
- A Green Pool: What to Do FirstThe order for bringing a green or cloudy pool back — test, brush, shock, filter continuously, retest — before reaching for an algaecide.
- How to Lower pH in a Pool: the Order, Not a DoseThe sequence for lowering pool pH safely — alkalinity first, small doses of acid, retest — and why this site prints no acid dose for a pH move.
- How to Raise Alkalinity in a PoolThe order for raising total alkalinity with baking soda or soda ash, why it comes before pH, and where the pH and alkalinity calculator picks up the dose.
- Never Mix These Pool ChemicalsWhy pool chemicals that look like ordinary powders and liquids can react violently together, with real incidents from EPA's own safety alert.
- Opening and Closing a Pool: the OrderThe sequence for opening and closing a pool each season — clearing debris, running the filter, then balancing chemistry — not a winterization how-to.
- Reading a Pool Chemical LabelHow to find the active-ingredient percentage, the signal word and the re-entry limit on an EPA-registered pool chemical label, using this site's saved labels.
- What Cyanuric Acid Does in a PoolHow cyanuric acid stabilizes chlorine against sunlight, why it isn't free, and what the 45:1 ratio and the 90 ppm ceiling are protecting against.