How to Open a Pool in the Spring

In this guide: Remove the cover · Top up the water · Reconnect equipment · Balance & shock · Get it clear · Calculators

Opening is the reverse of winterizing, done in order so you don't fight yourself. Start a week or two before you actually want to swim — clearing the first bloom of the season takes a few days of filtering. Do it too late and you're opening a green pool.

1. Clean and remove the cover

Pump off standing water and sweep debris before you pull the cover, so none tips into the pool. Clean, dry, and store the cover so it lasts another season. Remove any winter plugs and the freeze-protection gizmos from skimmers and returns.

2. Top the water back up

Winter evaporation and any water you lowered for closing means the level is usually below the skimmer. Refill to the middle of the skimmer opening — that can be a lot of gallons on a big pool, so it's worth knowing the cost of tap fill versus a water-delivery truck, and roughly how many hours the hose will run.

3. Reconnect and start the equipment

Reinstall drain plugs in the pump, filter, and heater; reconnect the returns; open valves; and prime the pump before starting it. Check for leaks at every fitting you touched. Once it's running, set your daily run time to hit at least one turnover.

4. Test, balance, and shock

Test the water (or take a sample to a shop for a full panel). Balance alkalinity first, then pH, then bring sanitizer up. Finish with a shock dosed to your full volume to clear the winter's organic load — do it at dusk and run the filter overnight.

5. Filter until clear

Run the pump continuously for the first day or two, brushing and cleaning the filter as needed. The water often goes cloudy right after shocking as dead organics get oxidized — that's normal, and the filter will clear it. Don't swim until free chlorine settles back into range and the water is clear.

Do the math on this page

These calculators turn the steps above into your exact numbers: