Known Limitations
Purpose
This page documents known limitations that may affect the accuracy or applicability of WaterBalanceTools calculators. No calculator is appropriate for all situations, and users should understand these limitations before relying on results.
Water Testing Variability
Test results vary based on the testing method, reagent freshness, sample temperature, and operator technique. Two tests on the same water sample may produce slightly different results. Always use fresh reagents, follow the test kit instructions precisely, and take multiple readings if results seem unexpected.
Environmental Effects
Environmental conditions affect pool chemistry in ways that calculators cannot predict: heavy rain dilutes and acidifies pool water; high UV index accelerates chlorine consumption; wind increases evaporation and affects chemical dosing; heavy bather load introduces ammonia compounds and other chlorine demand; fallen leaves and debris introduce phosphates and organic matter.
Temperature Effects
Water temperature affects chemical reaction rates, chlorine demand, and LSI. Calculators use the input temperature to account for some temperature effects, but rapid temperature changes between testing and treatment will reduce accuracy. Hot tub chemistry is particularly sensitive to temperature — test immediately before treatment when possible.
Product Concentration Differences
Dosage calculations assume products at their labeled concentration (e.g., 10% for liquid chlorine, 65% for calcium hypochlorite). Actual concentration may vary by brand, age, and storage conditions. Liquid chlorine degrades approximately 10–15% per month at room temperature and faster in heat. Always use fresh products and check labels.
Manufacturer Variations
Salt chlorinators have manufacturer-specific salt ranges and operating parameters. The dosage calculator uses typical coefficients but your system may require adjustment. Always consult your equipment manual and verify with a follow-up test.
Pool-Specific Conditions
Pool surface type, equipment design, hydraulic dead zones, and previous chemical history all affect real-world results. A plaster pool with high calcium history may need different treatment than a new vinyl pool. Calculators cannot account for these pool-specific factors.
Calculator Limitations
Volume calculations for irregular shapes are approximations. pH adjustment calculations are most accurate within ±0.5 pH units of the target. Shock calculations assume the water will be tested again 24 hours later. CYA calculations assume slow, complete dissolution over 24–48 hours. Multi-step corrections (adjusting multiple parameters simultaneously) may produce less accurate results than sequential single-parameter corrections.