Equipment and field

Pool Opening Checklist for Service Companies

A spring pool opening checklist in working order, from cover removal to first chemical balance, with a dosing example and GFCI stop points.

An opening visit is where good winterizing pays off and bad winterizing shows up. A repeatable order keeps you from starting a pump with a plug still in the line or dosing water that is not circulating. This page assumes a pool in a climate with a closing season. Some regions never close pools at all.

Before you start

Walk the pool and equipment pad. Take photos of the cover, the water, and the equipment before you touch anything. If the pool was covered, photos help if the customer asks later why it is green.

Check for hazards. Look at the cover for standing water, debris, and wildlife. Never walk on a cover. Keep people and pets away.

Order of work

Step	Task	Notes
1	Clear the cover	Pump off standing water, brush debris, then fold or remove the cover
2	Clean and store the cover	Dry it fully before storing, so it does not mold
3	Reinstall fittings	Return fittings, skimmer baskets, ladders, rails, and weirs
4	Remove winter plugs	Pull plugs from skimmer lines, returns, and pump housing, and note where they go
5	Set water level	Fill to the middle of the skimmer opening
6	Reassemble equipment	Pump drain plugs, unions, filter parts, heater drains, salt cell
7	Check electrical	Look, test the GFCI, and only then restore power
8	Prime and start	Open valves, prime the pump, bleed air, check for leaks
9	Check pressure	Record the clean filter pressure
10	Test and balance	Follow the order below
11	Brush and vacuum	Remove debris and dead algae
12	Report	Photos, readings, and what you did

Steps 6 to 8 are where equipment gets damaged. Work slowly.

Electrical check

Visually check the equipment pad and the wiring. Look for chewed or damaged wire, corrosion, signs of water, and burn marks.

Test the GFCI according to its instructions before you restore power to the equipment, typically by pressing the test button and confirming that it trips, then reset it.

Stop and call a licensed electrician if:

A GFCI will not reset or will not trip when tested.
A breaker trips when you turn the equipment on.
You see damaged, burned, or rodent-chewed wiring.
Water has gotten into a control box, motor, or junction box.

Do not bypass a GFCI or breaker. Rules about who can do electrical work vary by state, so check yours.

Gas heater

Do not light a gas heater yourself if anything seems wrong. If you smell gas, leave the area and call your gas utility or 911 from a safe distance. For heater problems after startup, see pool heater won't fire. Leave gas supply, burner, and valve work to licensed pros.

Prime and start

Check that the pump basket is clean, the lid O-ring is lubricated, and the drain plug is in.
Open the suction and return valves.
Fill the pump basket with water, seat the lid, and start the pump.
Open the filter air relief valve and close it when water flows steadily.
Walk the equipment and check each union and plug for leaks.
Record the filter pressure as your clean baseline.

If the pump does not prime, use the checks in pump not priming.

Test and balance in order

Test all of these after the pump has run for a few hours, and test before you dose anything: free chlorine, combined chlorine, pH, total alkalinity, calcium hardness, CYA, and salt if relevant.

Adjust in this order:

Total alkalinity. It anchors pH. The target is 60 to 120 ppm, with 80 to 120 common for plaster pools with trichlor use.
pH. Aim for 7.2 to 7.8, with 7.4 to 7.6 ideal.
Calcium hardness. 200 to 400 ppm for plaster, 150 to 250 for vinyl and fiberglass.
CYA. 30 to 50 ppm, or 60 to 80 ppm for salt chlorine generators.
Free chlorine. 1 to 4 ppm, and keep it about 7.5% of CYA or more.

Local code may differ. Retest between steps rather than dosing everything at once. Add chemical to water, follow the label and SDS, and never mix products.

Worked example

A 20,000 gallon pool opens with free chlorine at 0 ppm, CYA at 30 ppm, and a little algae. You decide to bring free chlorine to 5 ppm to start. That is 5 ppm.

Liquid chlorine at 12.5% needs about 10.2 fl oz per ppm per 10,000 gallons.
For 20,000 gallons, that is about 20.4 fl oz per ppm.
For 5 ppm, that is about 102 fl oz, a little under 1 gallon.

Split it if the water is cold or the pool is green, and retest. For a pool that opens green or cloudy, see green pool cleanup. If free chlorine drops quickly after dosing, check combined chlorine and plan a breakpoint.

Mistakes to avoid

Dosing before circulation. Chemicals pooled near a return give you bad readings.
Forgetting a winter plug. A plug left in a return line or pump port blocks flow. Count plugs out and in.
Skipping the GFCI test. Check it before restoring power.
Draining a high pool without checking. Local rules may limit where water can go.
Walking on the cover. Keep clear of it until it has been cleared or removed.
Promising a clear pool date. Water conditions after winter vary, so promise next visit's retest instead.

Pricing and scope

Opening scope and price vary by region and by what is included. Decide before you quote whether the visit includes cover removal, chemical start-up, and the first week's follow-up. Put it in writing, and see pool service contract for the clauses that help.

Common questions

What is the first thing to do when opening a pool?

Clear and remove the cover safely, then reinstall fittings and plugs, set the water level, and check the equipment before you start the pump. Chemistry comes after circulation is running.

How long does it take to clear a pool after opening?

It depends on the water's condition, temperature, and how well the pool was closed. Plan for the filter to run continuously and retest each visit rather than promising a date.

In what order do I balance water at a pool opening?

Test everything, adjust total alkalinity first, then pH, then calcium hardness and CYA, and bring free chlorine up last or alongside once circulation is running. Retest between steps.