Short answer
Turn off the pump and breaker, open the air relief to drop pressure to zero, and drain the tank. Remove the lid or valve, cap the standpipe, and scoop or vacuum out the old sand down to the laterals without bending them. Rinse, check every lateral, refit the drain plug, fill the tank about half with water, then pour the label amount of #20 sand with a dust mask on. Refit the lid with a lubed o-ring, backwash 2 to 3 minutes, rinse 30 seconds, then filter and note the clean pressure.
What you need
- Pool filter sand the amount on your filter label, usually 50 lb bagsFind it
- Dust mask N95 or better, for pouringFind it
- Wet/dry shop vac or a scoop and a bucketFind it
- Lid o-ring replace while the tank is openFind it
- Silicone lubricant for the o-ring and drain plugFind it
- Spare laterals in case one cracksFind it
The steps
Turn off the pump and the breaker
Switch the pump off, then cut power at the breaker so nobody turns it back on while the tank is open.
Release the pressure
Open the air relief valve on top of the filter until the gauge reads 0 psi. Water may spray, so keep your face clear.
Drain the tank
Remove the drain plug at the bottom of the tank and let the water run out. Some filters drain sand and water through the same port.
Open the tank
Unscrew the lid, or for a top-mount filter, disconnect the plumbing and lift off the multiport valve. Lay a cloth over the rim of a fiberglass tank to avoid splinters.
Cap the standpipe
Cover the open top of the standpipe with the sand shield or tape so no sand falls into it. Sand in the standpipe goes straight back to the pool.
Remove the old sand
Scoop or vacuum the sand out, working down to the top of the laterals. Go gently near the bottom: laterals are fragile. If the sand is caked, soak it with a 50/50 vinegar solution rather than chipping at it.
Clean and inspect
Rinse the tank and laterals with a hose and drain again. Check every lateral for cracks or missing slots and replace any that are damaged. Confirm the laterals point down.
Refit the drain plug
Lube the drain plug o-ring with silicone lubricant and screw it back in.
Fill the tank about half with water
This cushions the laterals when the sand lands on them. Hayward and Inyo Pools both call for it.
Pour the sand, mask on
Center the standpipe and pour the label amount of #20 pool filter sand slowly, through a cut corner of the bag. Level it. It should reach about the center of the tank flange, no higher.
Close it up
Remove the standpipe cover, refit the diffuser and air relief tube, clean the threads, and fit the lid or valve with a lubed o-ring. Replace the o-ring if it is flat or cracked.
Backwash
Set the valve to BACKWASH with the pump off, restore power, start the pump, and bleed air at the relief valve until water spurts, then close it. Backwash for 2 to 3 minutes, until the sight glass runs clear.
Rinse
Pump off, set the valve to RINSE, run for about 30 seconds to a minute, pump off again.
Filter and note the pressure
Set the valve to FILTER and start the pump. Write down the gauge reading: that is your clean pressure. Backwash again when it reads 6 to 8 psi higher.
Where these steps come from
The sequence follows Inyo Pools’ Triton II sand change guide and Hayward’s S200 manual, which covers filling half with water, the sand level at the flange, the 2 minute first backwash, and the 6 to 8 psi rule. Your filter’s manual may differ, especially for side-mount valves and Intex pumps; follow it where it does.
How much sand to pour
The amount on your filter label. If it is missing, the sand chart and the calculator give published figures by model and tank size. Switching media? Glass takes about 70 to 80 percent of the sand weight and zeolite about half: see sand vs glass vs zeolite.
Brand notes
- Hayward: Hayward sand filter sand change.
- Pentair: Pentair Triton II and Sand Dollar.
- Intex: sand for Intex sand filter pumps.
See #20 pool filter sand on Amazon
Questions people ask
How long does it take to change pool filter sand?
Plan on two to four hours for most residential filters. Removing old sand is the slow part, especially if it has hardened. Small above-ground tanks go faster.
What do I do with the old sand?
Old pool sand is usually fine as fill or under pavers once dried, but check your local rules for disposing of material that has been in treated pool water. Do not dump it in a storm drain.
How do I get hard, caked sand out?
Do not chip at it with a hammer or chisel: Inyo Pools staff warn that can break the laterals. They suggest soaking it with a 50/50 vinegar solution first, then scooping as it loosens.
Do I need to backwash after changing the sand?
Yes. Hayward’s manual recommends an initial backwash of at least 2 minutes once flow is steady, to flush fines and impurities out of the fresh sand, followed by a rinse.
Why is there sand in my pool after changing the sand?
A little after a fresh fill can be fines that the first backwash missed: backwash and rinse again. If sand keeps coming, a lateral may have cracked during the change. See the sand in the pool guide.
Sources
Last reviewed October 12, 2026. Sand amounts and listings change; check your filter’s label or manual before you buy, and follow the maker’s instructions.