Should you repair or replace your pool filter?
Updated August 2026
← Every repair-or-replace call
Nearly every pool filter problem is a media or seal job, so plan on $50–300 for new cartridges, sand, or DE grids and keep the tank; replace the $300–1,200 tank only when it cracks, the laterals break, or the filter is undersized for the pool. The tank is a pressure vessel that commonly serves 5–10 years or longer, while the media inside it is a consumable: cartridges last 3–5 years, sand 5–7, and DE grids 5–10. Pressure that climbs straight back up after a cleaning is a media message. A tank that is cracked or bulging is a safety problem and comes out of service the same day.
The short version
Diagnose by asking which layer failed. The media layer wears out on a schedule and is meant to be renewed, at $50–120 for a cartridge, $75–150 for a load of sand, or $150–300 for a grid set. The seal layer, meaning tank O-rings, clamp bands, and the multiport spider gasket, leaks and gets rebuilt for $20–150. Neither layer justifies a new filter. The vessel layer is the exception, and it is not negotiable. A hairline crack in the tank, a broken lateral spitting sand into the pool, or a clamp band that no longer draws tight is structural, and a housing running at 20–30 psi can fail violently. Replace then, whatever the age, and size the new tank generously.
Your situation, decided
| Situation | Verdict | Why |
|---|---|---|
| Pressure 8–10 psi over clean, flow getting weak | Repair (clean media) | Normal loading; backwash or soak the cartridge first |
| Pressure returns within days of every cleaning | Repair (new media) | Media is spent: $50–120 cartridge, $75–150 sand, $150–300 grids |
| Water weeping from the tank band or lid | Repair | A $20–60 O-ring or clamp band, seated with proper lubricant |
| Sand blowing back into the pool | Repair | A cracked lateral or standpipe, replaced during a sand change |
| Water bypassing to waste through the multiport | Repair | A $30–150 spider gasket or valve rebuild kit |
| Tank cracked or bulging, or the band will not hold | Replace | A pressurized vessel that can let go; stop using it now |
| Filter undersized, cleaning needed every week | Replace | A larger $300–1,200 tank cuts cleanings and eases the pump |
What each path costs
Repairs typically run $50–300; a replacement is $300–1,200 installed. Filter tanks run 5–10 years or more, while the media is consumable at 3–5 years for cartridges, 5–7 for sand, and 5–10 for DE grids. Price your own number on the home maintenance cost calculator before you commit either way.
The repair-or-replace call is easy when you know the unit's age and service history. OnOtto keeps both, plus the maintenance that delays this decision for years.
Start your home's service log, freeFrequently asked questions
How do I know a cartridge is worn out rather than just dirty?
Watch how long a cleaning holds. A dirty cartridge returns to its clean starting pressure after a soak and rinse and stays there for weeks. A worn one climbs back within days, because the pleats have lost their shape or the fabric has gone slick with body oils. Inspect the pleats as well: flattened, torn, or permanently gray fabric with frayed ends is finished. Most cartridges reach 3–5 years with rotation, and our cartridge guide covers the swap interval.
Is a cracked filter tank actually dangerous?
Yes, and it is one of the few pool repairs to treat as urgent. The tank holds 20–30 psi in normal service and more if air is trapped or the lid is clamped incorrectly, and a compromised shell or band can let the lid separate under that pressure. Shut the pump off, open the air relief, and leave the filter offline until it is replaced. Do not seal a hairline crack with epoxy and keep swimming. A new tank at $300–1,200 is the only correct answer.
Should I switch from sand to cartridge, or the other way?
Choose by how you prefer to spend the time. Sand backwashes in two minutes but wastes water and filters coarser. Cartridges catch finer debris and use no backwash water, though you pull and hose the elements several times a season. DE gives the finest water and the most work. If the tank is being replaced anyway, that is the moment to change types. Whichever you pick, size it above the pump flow rate; our filter lifespan guide compares how each media holds up.
What happens if I simply never clean it?
The pump pays before the filter does. A loaded filter drives pressure up and flow down, so the pump works against resistance that cooks its shaft seal and shortens the motor's life, while the water turns cloudy because turnover has collapsed. Cleaning costs between nothing and $30 on a schedule, laid out in the cleaning guide. The full damage tally sits in our breakdown of the cost of neglecting a pool filter.