Wait about 20-30 minutes.

Yes, you can swim after adding baking soda, but give it time to dissolve and circulate first. Baking soda raises alkalinity quickly and is safe for swimmers in normal doses. But if you dump it in and jump right in, you might get undissolved powder on your skin or the pool floor. Run the pump for half an hour, test the water if you’re feeling thorough, and then go ahead.

Your pool will be fine. Your swim will be fine. You don’t need to wait 24 hours.