How to open your pool for summer

Opening day goes faster when you do things in the right order. The big rule: get the equipment running properly before you start pouring in chemicals. Every manufacturer guide we checked puts the chemistry after the pump and filter are back up.

This combines the opening steps from Hayward, Pentair and the pump manuals themselves. There's a printable checklist version to take outside.

1. Get the cover off

Pump the standing water off the top of the cover and sweep or net off leaves before you pull it, so the mess doesn't end up in the pool. Hayward and Pentair both start here. Clean the cover and let it dry completely before folding it away for the summer.

2. Bring the water up

Top the pool up to its normal level. Leslie's says the middle of the skimmer opening. Hayward's pump manual is firm that water has to be above all suction openings before the pump runs.

3. Put the equipment back together

Pull the winterizing plugs out of the skimmers and return lines. Put the drain plugs back in the pump and filter (Pentair says to do this "before running anything"). Reinstall ladders, rails, the diving board and any return fittings you removed. Hayward also says to check that the heater is free of debris and has proper clearance from anything that could burn.

4. Prime the pump and start it

Take this step slowly. Both pump manuals say the same thing: fill the strainer pot with water before you start the pump, and never run it dry. Hayward's adds that every suction and discharge valve must be open when you start it.

Make sure the pump lid and the filter lid or clamp are fully secured. Pentair's pump manual warns that the system is under pressure and to stand clear of the pump and filter during start-up. Then open the air relief valve on top of the filter, start the pump and wait for water to spray from the relief valve, then close it. Priming can take a few minutes; the allowed time varies by pump, so check yours. If it won't prime, turn it off and see the FAQ below.

Once it's running, walk around the equipment and look for drips and leaks. Note the filter's pressure reading. That's your clean baseline, and you'll clean the filter when it climbs 8 to 10 psi above it.

5. Clean the pool

Skim, brush the walls and floor, and vacuum. If the floor is heavy with debris or the water is green, Hayward's guide says to vacuum to waste so you don't load up the filter.

6. Test and balance

Check that your test kit and chemicals haven't expired; Hayward calls this out. Then test free chlorine, pH, alkalinity, calcium and stabilizer.

Fix alkalinity first, because the Pool & Hot Tub Alliance says to correct alkalinity before pH. Then pH. Calcium and stabilizer can follow.

Add one chemical at a time with the pump running, and let each one circulate before the next. Wear goggles and gloves. The CDC says never to mix pool chemicals, especially acid and chlorine. The ideal levels chart has the targets, and each has a calculator. If you don't know your gallons, start with the pool volume calculator and save the number so every other calculator fills it in.

7. Shock and filter

Once the water is balanced, shock it. Hayward and Leslie's both include this step. For a 20,000-gallon pool, raising free chlorine from 0 to 10 ppm takes about 2 gal of 10% liquid chlorine, or 2 lb 9 oz of 65% cal-hypo. The shock calculator gives your exact dose.

Run the filter continuously until the water is clear, cleaning it as the pressure rises. If the pool opened green, follow the green pool guide instead.

8. Retest before anyone swims

Swim only when you can clearly see the bottom and free chlorine is back in range. Public pool codes, including CDC's, close a pool when the main drain can't be seen from the deck. Free chlorine should be at least 1 ppm, or at least 2 ppm with stabilizer (CDC), and no higher than your product label's swim limit. On the HASA liquid chlorine label, that limit is 4 ppm.

Safety check while you're at it

Opening day is the right time to walk the safety gear.

1. Drain covers: the CPSC says drains should have covers that meet federal safety standards. Don't use the pool if a cover is cracked or missing.
2. Fence and gates: CPSC guidelines call for a fence at least 4 feet high, with gates that close and latch by themselves. Your local code may require more.
3. Door alarms on doors that lead to the pool, also from CPSC guidelines.
4. Ladders and rails tight and secure.
5. A plan for supervision. The CPSC recommends naming an adult "Water Watcher" whenever kids are swimming, and learning CPR.

Print the opening checklist and the test log, and you're set for the season.