Symptoms
- Water looks hazy, milky, or dull instead of clear
- Can't see the bottom of the pool clearly
- Hazy look worsens after rain or heavy pool use
Likely causes
- CommonLow or imbalanced chlorine levelChlorine that's too low lets algae and bacteria cloud the water.
- CommonDirty or undersized filter not removing fine particlesA clogged or short filter cycle leaves fine debris suspended.
- PossibleHigh pH or total alkalinityImbalanced water chemistry can cause minerals to cloud the water.
- PossibleFine dust, pollen, or sunscreen residue overwhelming the filterVery fine particles pass through some filters without a clarifier.
What to do
- Test the water with a home test kit or take a sample to a pool store for pH, chlorine, and alkalinity readings.
- Shock the pool with the recommended dose of chlorine shock if chlorine is low or algae is suspected.
- Clean or backwash the filter to remove trapped debris that's reducing its effectiveness.
- Run the pump and filter continuously for 24–48 hours after shocking to fully circulate and clear the water.
- Add a pool clarifier or flocculant if cloudiness persists, which helps fine particles clump for the filter to catch.
- Vacuum any settled debris from the bottom once the water clears.
Tools and parts
- Pool test kit
- Pool vacuum
- Filter cleaning supplies
Pool shock treatmentSearch: “pool shock chlorine treatment”
Pool clarifierSearch: “pool water clarifier”
When to call a pro
If water stays cloudy after balancing chemicals and cleaning the filter, a pool service technician can check for filter or equipment issues.
Safety
Use caution
Handle pool chemicals in a ventilated area, never mix different chemicals together, and keep children and pets away from freshly treated water until levels are safe.