Opening a pool: step-by-step (2026)

When to open

Open when daytime air hits 65 to 70 degrees and stays there for a week. Sooner and you fight cold-water algae problems with a pump that struggles in the chill. Later and you fight a serious algae bloom because the cover trapped warmth.

What you need

Cover pump (or a submersible pump)
Skimmer net
Pool brush
Test kit
2 to 4 gallons liquid chlorine
2 lbs sodium bicarbonate
1 quart muriatic acid
Polyquat 60 algaecide (optional but smart)

Step-by-step

1. Pump off the cover (cover still on pool)

Use a cover pump to drain standing rain water until you can lift the cover safely. Skim debris off the cover surface. Do not let dirty cover water into the pool.

2. Remove the cover and clean it

Pull the cover off, rinse with a hose, lay flat to dry. Fold or roll once dry and store in a sealed container so mice cannot nest in it.

3. Top off the water

Fill to the middle of the skimmer opening. Below that and the pump will suck air at startup.

4. Reinstall plugs and equipment

Pull winter plugs from skimmers and returns. Reinstall any baskets, eyeball fittings, and pressure gauge. Reinstall the pump drain plugs.

5. Prime the pump

Fill the pump basket with water from a hose. Close the lid tight. Set the multiport to filter. Start the pump. It should pull a prime in 60 seconds. If not, you have a suction-side air leak.

6. Run the filter for 24 hours

Just circulate. Do not chase chemistry yet.

7. Test and balance

After 24 hours, test all five values. Bring alkalinity to 80 to 120, then pH to 7.4, then chlorine to 3 ppm. Add CYA if needed.

8. Shock

Shock to 10x your CYA level. Brush. Run the pump 24 hours.

9. Clear and clean

Vacuum any sediment. Clean the filter. Test daily for the first week and adjust as needed.

Common opening mistakes

Removing the cover before draining rain water (dumps mud into the pool)
Adding shock without balancing pH first
Skipping the algaecide on a pool that was green at closing
Letting the cover sit folded wet (mildew)

When to call a pro

Open it yourself unless equipment is broken or the pool is solid green. A pool service charges $300 to $600 for an opening. The same money buys you 6 to 8 months of weekly chemistry yourself.

Frequently asked questions

How long does it take to open a pool?

Half a day for the physical work. 5 to 7 days to fully clear if the pool was closed properly. Up to 2 weeks if the pool came up green.

Should I open the pool myself or hire someone?

Most owners can do it in a half day. A pool service charges $300 to $600. Worth it the first year if you are unsure, then learn it for next year.

What if the pool is green when I open it?

Run a full SLAM (shock at 10x CYA for 3 to 5 days, brush daily, clean filter daily). See our green pool recovery guide for the schedule.

Do I need to drain my pool to open it?

No. Top up to the middle of the skimmer. Draining is only needed if CYA is over 60 ppm or the water is heavily contaminated.

When should I open my pool?

When daytime air hits 65 to 70 degrees and stays there for a week. In Texas and Florida, that is March. In the Northeast and Midwest, mid-April to early May.

Can I open a pool with a damaged cover?

Yes, but inspect it. If the cover let rainwater past or had a tear, expect a green or cloudy pool and plan for a longer recovery.

Is it better to open early or late?

Early is easier on chemistry. The cover traps warmth that wakes algae. Open at 65 degrees rather than waiting for 80.

Opening a pool for the season: step-by-step