Key takeaways
- Round pool: diameter × diameter × depth × 5.9 = gallons
- Oval pool: length × width × depth × 6.7 = gallons
- Rectangular frame pool: length × width × depth × 7.5 = gallons
The best sand filter for an above ground pool depends on pool size and wall type: the Intex Krystal Clear SX2800 is the best all-in-one pump and filter for soft-sided and frame pools up to roughly 12,000 gallons, the larger Intex Krystal Clear 3,000 GPH model suits bigger Intex and Bestway pools, the Hayward ProSeries S166T or S244T tank is the long-life choice for hard-wall pools, and the Pentair Sand Dollar SD40 or SD60 kit is the durable one-piece-tank alternative. Sizing it correctly matters more than the brand.
Step one: work out your pool volume
Every sand filter is rated by the maximum pool volume it can turn over. Use these standard formulas with average water depth in feet (usually 6 to 8 inches less than the wall height):
- Round pool: diameter × diameter × depth × 5.9 = gallons
- Oval pool: length × width × depth × 6.7 = gallons
- Rectangular frame pool: length × width × depth × 7.5 = gallons
Most pool care guides aim to circulate the full volume at least once every 8 hours. Divide gallons by 8 to get the minimum real-world flow in gallons per hour (GPH).
| Pool | Water depth | Approx. gallons | Min. flow for 8-hr turnover | Suggested filter class |
|---|---|---|---|---|
| 12 ft round | 2.5 ft | ~2,100 | ~265 GPH | Small combo (1,500–2,100 GPH) |
| 15 ft round | 3.5 ft | ~4,650 | ~580 GPH | Combo, 2,100–2,800 GPH |
| 18 ft round | 3.5 ft | ~6,700 | ~840 GPH | Combo, 2,800 GPH or 16 in tank |
| 24 ft round | 4 ft | ~13,600 | ~1,700 GPH | Large combo or 19–24 in tank |
| 18 × 33 ft oval | 4 ft | ~15,900 | ~2,000 GPH | 22–24 in tank, 1–1.5 HP pump |
| 12 × 24 ft rectangular frame | 4 ft | ~8,600 | ~1,080 GPH | Combo, 2,800–3,000 GPH |
Pump GPH ratings on the box are measured with almost no resistance. Hoses, the filter bed, and the height of the return reduce real flow, often by a third. That is why the suggested classes above are well above the bare minimum. Oversizing the filter tank is fine; oversizing the pump alone just wastes electricity and can channel the sand.
The main contenders
| Filter | Type | Sand needed | Rated pool size | Hose / plumbing | Typical price |
|---|---|---|---|---|---|
| Intex Krystal Clear SX2800 | Pump + filter combo | ~55 lb | Up to ~12,800 gal | 1.5 in Intex hoses | $200–$300 |
| Intex Krystal Clear 3,000 GPH | Pump + filter combo | More than the SX2800; per manual | Up to ~19,600 gal | 1.5 in Intex hoses | $300–$400 |
| Bestway Flowclear sand filter pump | Pump + filter combo | Varies by size | Small to mid Bestway pools | 1.25–1.5 in hoses | $150–$300 |
| Hayward ProSeries S166T | Tank only, 16 in | ~100 lb | Up to ~15,000 gal | 1.5 in threaded | $350–$450 |
| Hayward ProSeries S244T | Tank only, 24 in | ~200 lb | Up to ~24,000 gal | 1.5 in threaded | $550–$800 |
| Pentair Sand Dollar SD40 / SD60 | Tank, sold with pump kits | Per manual, roughly 100–200 lb | Mid to large AG pools | 1.5 in threaded | $400–$900 with pump |
Which one fits your pool
Soft-sided and metal frame pools: Intex Krystal Clear SX2800
This is the plug-and-play answer for most Intex and many Bestway pools. It comes with the pump, a 6-function valve and a timer, connects directly to standard 1.5 inch soft hoses, and sits on its own base. Its 16 inch class tank is small, so backwashing is more frequent than with a large Hayward tank, but for pools up to about 18 to 20 feet it keeps water clear when sized correctly.
Larger Intex frame pools: Intex Krystal Clear 3,000 GPH
For 20 to 24 foot rounds or large rectangular frame pools, the bigger Intex combo adds flow and filter area. Some models include a saltwater-ready configuration or pair with Intex saltwater systems.
Hard-wall steel or resin pools: Hayward ProSeries
Hayward tanks are what pool shops install on permanent above ground pools. The S166T suits pools up to about 15,000 gallons; the S244T is the better match for 24 foot rounds and 18 × 33 ovals. You buy the pump separately, typically a 1 to 1.5 HP above ground pump, which lets you choose a variable-speed model to cut running costs. Parts such as laterals, valves and gaskets are easy to find, and these tanks commonly last well over a decade.
One-piece tank preference: Pentair Sand Dollar
The Sand Dollar uses a blow-molded, one-piece tank that does not corrode, with a six-position valve and a combined water and sand drain that makes winterizing easier. It is commonly sold as a kit with a matched pump, which simplifies buying.
Decision matrix
| Your situation | Best match | Why |
|---|---|---|
| First pool, 15–18 ft Intex frame | Intex SX2800 | Correct hose size, all in one box |
| 20–24 ft Intex or Bestway | Intex Krystal Clear 3,000 GPH | More flow, larger tank |
| Permanent 24 ft round or 18 × 33 oval | Hayward S244T + 1–1.5 HP pump | Capacity, longevity, parts |
| Renter or seasonal setup | Intex SX2800 | Light, easy to drain and store |
| Wants a complete pro-grade kit | Pentair Sand Dollar kit | Matched pump, rust-proof tank |
Setup realities
- Sand weight: 50 lb bags are typical. A 24 inch tank means carrying about four bags. Use #20 silica pool filter sand, never play sand.
- Placement: set the filter on a level paver or slab, at or slightly below water level, and at least 4 to 6 feet from the pool wall where local electrical codes require it. Plug into a GFCI-protected outlet.
- Protect the standpipe: fill the tank partly with water before adding sand so the laterals at the bottom are not cracked by falling sand.
- Backwash on pressure, not on a calendar: note the gauge reading on clean sand, then backwash when it rises about 8 to 10 PSI above that baseline, followed by a rinse cycle.
- Glass media: many owners switch to filter glass media, which typically needs about 20 percent less weight than sand and filters slightly finer. Follow the filter maker’s guidance before switching.
Ownership and wear
Sand lasts roughly 3 to 5 years before its edges round off and it filters poorly. The multiport valve’s spider gasket and the tank O-ring are the first parts to leak; a light coat of silicone pool lubricant on each, never petroleum grease, extends their life. In freezing climates, drain the tank, remove the drain plug and store combo units indoors.
Bottom line
Choose the Intex Krystal Clear SX2800 for most soft-sided and frame pools up to about 18 feet, the 3,000 GPH Intex model for larger Intex pools, and a Hayward ProSeries or Pentair Sand Dollar tank for permanent hard-wall pools. Calculate your gallons first, then size up one step rather than down.
