Shock your above-ground pool at night, after balancing pH.

Yes, but timing and chemistry matter more than the shock itself.

First, test your water. If pH is above 7.6 or alkalinity is off, fix that first — shock works best when pH is 7.2–7.4. Throw shock into unbalanced water and you’re just wasting money.

Second, do it at dusk. Sunlight burns off chlorine fast, so shocking in the morning means you lose half the punch. Evening gives the chemicals all night to work.

Follow the label dosage for your pool size. Don’t guess. Broadcast it around the edges while the pump runs — pour it into the skimmer and you risk damaging the filter. Let the pump run for at least 8 hours after.

You’ll know it worked when the water turns cloudy then clears up. Wait 24 hours before swimming.

If you skip the pH check first, you’re just making expensive cloudy water.