Intex Ultra XTR Frame 18 ft x 9 ft x 52 in Rectangular

The 26355EH is Intex's 18 by 9 foot Ultra XTR Frame pool sold as a set: a rectangular pool with a 52-inch wall, a galvanized steel frame, a 10-inch sand filter pump, a ladder, a cover and a ground cloth. It holds 4,545 gallons at Intex's 90% fill. Intex's own store lists it at $1,099.99, a hundred dollars more than the 18-foot round Ultra XTR set, which holds 6,981.

What is in the box, and what is not

• The pool: a 3-ply liner with white copings, horizontal beams, four corner joints, and 12 U-shaped side supports with restrainer straps.
• The Krystal Clear 10-inch sand filter pump, item 26643EG, with its hoses and fittings.
• A 52-inch ladder, item 28067, for one person at a time up to 300 lb.
• A pool cover and a ground cloth. The cover is not a safety cover.

Not in the box: the filter sand, which this pump needs 26 lb of, No. 20 silica sand with particles from 0.45 to 0.85 mm, or 18.5 lb of glass sand. Nor are there support pads, which most sites need, any pool chemistry, or glue for the patch kit.

How the rectangle stands up

A round Ultra XTR stands on vertical legs under T-joints. This one braces its wall with U-shaped side supports instead: four along each long side and two on each short side, each tied to the liner by a restrainer strap and a connecting rod.

That changes the ground work:

• Pads under every support, unless you are on concrete. On lawn, earth or asphalt, Intex requires a piece of pressure-treated wood, 15 by 15 by 1.2 inches, under each U-shaped support, recessed flush with the ground, the support centered on it and the grain running across the leg. Steel pads or reinforced concrete slabs also work. Slippery, smooth pads void the warranty, because the supports slide outward.
• Room to assemble. The liner lies flat while the supports go in, so Intex wants the ground cloth's edges 5 to 6 feet from any wall, fence or tree.
• The corners move. The four corner joints are meant to slide relative to the beams, and once the pool is full the walls lean inward. Intex says both are normal.

The rest matches Intex's round pools: ground that is absolutely flat and level, compacted and firm, and not mud, sand or loose soil; at least 4 feet from anything a child could climb; at least 6 feet from any outlet; and the one-inch test, where water that runs to one side means draining the pool and leveling again. Intex recommends two to four people and estimates 60 to 90 minutes for the pool before the pump goes on. The pool needs no tools; the pump needs a Phillips screwdriver.

The pump, and its three flow figures

Intex gives this set's pump three different flow figures in three places:

• The set's page: "pump flow rate: 1,200 gph".
• The pump's own page: 1,500 gph pump flow, 1,050 gph system flow and turnover, 0.25 HP, for pools from 2,800 to 8,400 gallons.
• The pump's manual: a maximum flow rate of 1,050 gph for certified model SF90110-2.

The figure that matters for running it is Intex's time table, which sets this pool at 5 hours a cycle, and the manual's limit of 12 hours a day. That is the same run time Intex gives the round 18-foot set with its larger pump; this pool holds about two-thirds as much water.

Running and backwashing work as on Intex's other sand filter pumps: backwash when the gauge reaches the yellow zone, with any pool cleaner taken off the line first; switch the pump off before turning the 6-way valve; check weekly that the inlet and outlet are clear. Intex says to replace the sand about every five years. This pump's maximum working pressure is 20 psi.

Winter

Intex's rectangular manual gives the same two options as its round one, and closing an above-ground pool sets them beside other makers' steps. Leave it up with clean, balanced water, the fittings plugged or plunger valves closed, the ladder and hoses removed, and an air pillow under a winter cover, which Intex says helps prevent ice damage. Or take it down: drain it, dry everything, dust the liner with talcum powder, fold it and store it between 32°F and 104°F.

Either way the pump comes indoors. Drain the tank, dry the parts, grease the O-rings and washers with petroleum jelly, leave the 6-way valve on N, and store the motor unwrapped between 32°F and 104°F; this pump's manual also says to cover the tank with a tarp. Letting water freeze in the filter damages it and voids the warranty, and the pool's warranty excludes freeze damage.

The 2025 compression strap recall

In July 2025 the CPSC announced recall 25-393, covering above-ground pools 48 inches and taller whose compression strap runs around the outside of the vertical legs, where it can give a child a foothold into the pool. Intex's recall page limits its share to:

• 48- and 52-inch Metal Frame and Ultra Frame pools sold before 2013.
• 48-inch Prism Frame and Ultra XTR Frame pools sold online by Intex in 2024 and 2025, at Walmart from February 15 to March 11, 2025, and in 2026 through certain liquidation stores in Texas and West Virginia or on eBay.

This set is a 52-inch Ultra XTR pool, which is not on that list, and Intex says pools 48 inches and taller sold after 2013 with straps running inside the legs are not included. Intex's "Identify Your Model" check on its recall page, listed with this page's documents, confirms a pool by model number, and its recall line is 1-800-549-8829.

Where Intex's documents disagree, or are unclear

• Pump flow. The set's page says 1,200 gph; the pump's page says 1,500 gph pump flow and 1,050 gph system flow; the manual gives a 1,050 gph maximum; the Amazon listing says 1,500. The pump's own web address still reads 1,200.
• "Our largest Ultra XTR Frame pool." The set's description calls this 18 by 9 foot pool Intex's largest. The rectangular manual covers 24 by 12 and 32 by 16 foot versions of the same pool.
• Assembly time. The listing says "ready for water in 60 minutes"; the manual estimates 60 to 90 minutes for the pool alone.
• Cartridges in a sand filter set. The rectangular manual tells owners to replace filter cartridges every two weeks and to discard the old one when winterizing. This set has no cartridge; follow the sand filter pump manual.
• The pump's page lists it as compatible with an "18ft x 9in" rectangular pool, a typo for 18 by 9 feet.