Find a Guide for Your Pool Problem
Pick the problem you’re seeing. Each guide starts with checks to make, then points you to a calculator when you need an amount.
Green Pool
Green water may be algae. Start with free chlorine (FC), CYA and a valid pH test. Follow the CYA-based treatment plan, retest for every addition and keep filtering until every completion check passes.
Cloudy Pool Water
Check free chlorine, pH and your filter before reaching for a treatment. The cloudy-water guide walks you through the next steps.
Algae Bloom (Mustard / Black)
For suspected mustard or black algae, identify the growth before increasing treatment strength. Follow the CYA-based algae plan and use cleaning methods suited to your pool surface. If growth persists, get professional advice; do not automatically multiply the chlorine target.
High CYA (stabilizer buildup)
As CYA rises, the chart calls for more free chlorine; there’s no sudden cutoff where chlorine stops working. Before lowering water to dilute CYA, have a qualified pool professional assess the risks to your shell, liner or walls.
Low or Zero Chlorine
Keep swimmers out if free chlorine is zero. Use fresh readings and measured CYA to calculate an addition. Before swimming, retest FC and pH, meet the chlorine label’s re-entry conditions and check that the water is clear with no visible algae.
Pool Opening Problems
If you lift the cover to green water or tests outside your target range, start with the opening guide. Inspect the pool and test the water before choosing the next step.
Pool Closing Checklist
Work through water chemistry, winterizing the lines, storing equipment and fitting the cover. Follow the instructions for your pool and equipment.