Free pool chemical dosing calculator

What this pool chemical dosing calculator accounts for

• Pool volume in gallons -- the starting point for every dosing calculation, since chemical addition is always per-volume. The built-in estimator handles rectangular, round, and oval pools.
• Current free chlorine level -- the measured ppm from the test kit or photometer, compared to the target range of 1.0 to 3.0 ppm for residential pools. Supports liquid chlorine, cal-hypo, dichlor, and trichlor tabs at their actual active-ingredient concentrations.
• Current pH -- the measured pH from the test kit, compared to the ideal range of 7.4 to 7.6. Low pH means adding soda ash; high pH means adding muriatic acid or dry acid dosed by the adjustment needed.
• Current total alkalinity -- the measured TA in ppm, compared to the target range of 80 to 120 ppm. TA buffers pH swings, so pools that swing pH every week are often fighting low alkalinity.
• Current calcium hardness -- the measured CH in ppm, compared to the 200 to 400 ppm target that prevents equipment corrosion and plaster etching. Soft water eats plaster; hard water scales heaters.
• Current cyanuric acid -- the stabilizer level in ppm, which affects how quickly the sun degrades free chlorine. The target is 30 to 50 ppm for outdoor pools. High CYA requires dilution, since no chemical removes it.
• Chemical product type -- liquid chlorine at 10% or 12.5%, cal-hypo at 65%, dichlor at 56%, and trichlor at 90% all have different active-ingredient concentrations, so the dose per 10,000 gallons differs for each product.
• Dose in ounces or pounds with large-correction warnings -- doses above 5 ppm chlorine or a pH swing above 0.6 units trigger a staged-addition warning, since large single corrections can stress the water and the equipment.