What Chlorine Products Leave Behind
Give common chlorine products the same sanitizing job, then see
which one adds CYA, calcium hardness, or salt over time.
Same chlorine today, different water chemistry later. This comparison shows what builds up when you use the same product week after week.
At 4.0 ppm FC per week for 8 weeks, trichlor adds about 19.4 ppm CYA to the water.
This is a chemistry comparison, not a dosing recommendation. It assumes no water is replaced and does not model product strength, pH, chlorine demand, rain, splash-out, backwashing, or fill water. Test the pool, follow the product label, and never mix chlorine products.
Chlorine products do more than add chlorine
Liquid chlorine, cal-hypo, trichlor, and dichlor can all supply free chlorine. They do not leave the same water behind. Repeated use can also add cyanuric acid, calcium hardness, or salt.
Trichlor and dichlor add CYA
Trichlor tablets and dichlor granules are stabilized chlorines. The stabilizer is part of the compound, so CYA rises as the product adds chlorine. For the same free-chlorine contribution, dichlor adds more CYA than trichlor.
Cal-hypo adds calcium hardness
Calcium hypochlorite supplies chlorine and calcium. This comparison expresses the calcium contribution as calcium hardness in ppm as CaCO3, the same convention used for pool-water testing.
Liquid chlorine leaves salt
Sodium hypochlorite becomes chloride after its available chlorine is spent. The model shows the minimum salt produced by that reaction. Commercial liquid chlorine can contain additional salt from manufacturing, so the actual increase can be higher.
How this comparison works
Select a chlorine product, set the free chlorine added each week, and choose the number of weeks. The large result is the estimated secondary material added over that period. Press Play the weeks to see it accumulate.
Pool volume is not needed here because both inputs and results are concentrations in ppm. This model compares chemical relationships; it does not calculate how much product to pour into a pool.
Calculate an actual treatment amount
Use the pool chemical dosage calculator when you know the pool volume and target change. If stabilizer is the concern, use the CYA calculator or check the free chlorine to CYA ratio.
Sources and model scope: The ratios are derived from molecular composition and available-chlorine equivalents using reference data for trichlor, sodium dichloroisocyanurate, calcium hypochlorite, and sodium hypochlorite. Product and safety language is checked against EPA labels for trichlor, dichlor, and cal-hypo.