Guides
Plain-English background to the formulas behind the calculators — from pool volume to salt, chlorine, alkalinity and heater sizing.
How to calculate your pool volume (gallons) by shapeCalculate pool volume in gallons for rectangular, round, oval and kidney pools from average depth and the standard 7.5 and 5.9 shape multipliers, with examples.How many gallons is my pool? Sizes and chartsFind how many gallons your pool holds from its size and shape, with a quick method, a reference chart of common pool sizes, and worked examples in US gallons.How much salt to add to a saltwater poolWork out how many pounds of pool salt to add to reach a target ppm, using the 8.34 lb/gal solute rule, with a worked example and a chart for common pool sizes.How to convert a pool to saltwater: how much salt you needConverting a chlorine pool to salt? Learn how much salt to add to reach target salinity from zero using the 8.34 lb/gal rule, and what the switch changes.How much chlorine to add to a pool (liquid, cal-hypo, dichlor)Calculate how much chlorine to add to hit a target free chlorine for liquid chlorine, cal-hypo and dichlor, using product strength % and ppm dosing math.How much shock does my pool need? Breakpoint explainedLearn how much shock to add to your pool, what breakpoint chlorination means, and how to size a dose for liquid chlorine or cal-hypo using free-chlorine math.How to lower or raise pool pH with acid and soda ashHow to adjust pool pH: lower it with muriatic acid, raise it with soda ash, why total alkalinity matters, and a worked estimate for a common correction.Total alkalinity: how much baking soda to addHow to raise pool total alkalinity with baking soda using the 1.5 lb per +10 ppm per 10,000 gallons rule, why TA buffers pH, and a worked example.Cyanuric acid (stabilizer): how much to add and how to lower itHow much cyanuric acid to add to protect chlorine from sunlight, using the +13 ppm per lb per 10,000 gallon rule, and why only dilution can lower CYA.What size pool heater do I need? BTU sizing explainedSize a pool heater in BTU/hr from your volume, temperature rise and target heat-up time, using the mass × specific heat formula, with a worked example.How long does it take to heat a pool?Estimate pool heat-up time from gallons, temperature rise, heater BTU/hr and efficiency, with the formula, a worked example and why real times run longer.Pool pump turnover, GPM and filter sizing basicsUnderstand pool turnover and GPM, size a filter from flow and design rate for sand, cartridge and D.E., and estimate pump energy, with worked examples.