Swimming After Chemicals – How Long Should We Wait?

The answer to this depends on which chemicals you are using. So let’s take a look at what you’re adding (and why) to see how much time should pass before resuming your wet ‘n wild poolside fun.

Pool Shock

If you’ve just given your swimming pool a heavy dose of chlorine to shock it into submission, then it’s wise to wait at least 24 hours before letting the kids back in. If you’re still not sure, then do a quick test and make sure that your chlorine levels are at a sensible 5 ppm or thereabouts. (To be fair, if you’ve gotten to the point where you’re using shock treatment, chances are good that your family won’t want to swim in the water anyway.)


If you’re adding algaecide – which is usually pretty safe to swim with, then wait at least 15 minutes before swimming. Too much algaecide will result in a little skin or eye irritation, so rather err on the side of caution.

Water Balancing Chemicals

If you’re working on balancing your pH or you’ve added clarifier, then give yourself at least 20 minutes to an hour before swimming.

Acid (Hydrochloric or Muriatic)

The very name warns us to be careful, so when adding acid to your pool you really want to give it time to run through the filter and disperse evenly throughout the water. Wait at least 30 minutes before allowing the family back in, but make sure that your pool pump is running and there are no blockages which may result in acid spots in the water.

Obviously, these are only guidelines.  The size of your pool and the amount of chemicals used will all factor into the overall safety of swimming after chemicals, so be cautious and make sure that you always read the labels on any chemicals that you use.