Complete Pool Guide Pool and hot tub troubleshooting

Pool and hot tub guides

All pool and hot tub guides

Step-by-step fixes for common pool and hot tub problems. Pick an area or search for the problem.

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Pool care

Pool problems, area by area

Hot tub care

Hot tub problems, area by area

Common pool and hot tub problems at a glance

The problems owners search for most, the causes to check first, and the page that walks you through them.

Problem Check first Where to go
Pool water is green Free chlorine, pump run time, a dirty filter Green and cloudy water
Pool water is cloudy Filter pressure and run time, pH, free chlorine Green and cloudy water
Chlorine will not hold or pH will not drop A fresh water test, stabilizer (CYA) level, total alkalinity Pool chemistry
Pump hums but does not run, or will not prime Breaker, water level, a full strainer basket, the lid O-ring Pool pump problems
Filter pressure too high or too low Clean or backwash the filter, then the skimmer and pump baskets Pool filter problems
Pool heater or heat pump not heating Water flow, the heater’s display or code, gas supply or air temperature Heater and heat pump
Salt pool losing chlorine or turning green Salt level, a scaled or worn cell, the cell’s output setting Salt system problems
Pool light out or robot cleaner stuck The GFCI and breaker, the cleaner’s filter and power supply Lights and cleaners
Hot tub foam or cloudy water Sanitizer level, the filter, soaps and lotions, how old the water is Hot tub water
Hot tub not heating The code on the panel, a dirty filter, low water, the high-limit Hot tub heating
Hot tub GFCI trips or jets are weak When it trips, an airlock after a refill, closed jets or valves Jets, pump and GFCI
Inflatable hot tub not heating The error code, the filter cartridges, the pump connections Inflatable hot tubs

Common questions

Where should I start when my pool or hot tub has a problem?

Start with a fresh water test and the filter. Low sanitizer, wrong pH and poor flow cause most water problems and many equipment errors. Then check breakers, valves and water level before you look at any part.

How often should I test pool and hot tub water?

The CDC advises checking free chlorine (or bromine) and pH before you get in. Hot tubs need closer watching than pools because the water is warm and the volume is small, so sanitizer gets used up fast. Test again after heavy use, rain or a party.

What test kit do I need?

A kit that reads free chlorine (or bromine), pH, total alkalinity and stabilizer covers most problems. Drop-based kits give finer readings than strips, which helps when the numbers are close to the edge of a range.