Hayward StarClear Plus Cartridge Filter

The StarClear Plus is Hayward's older single-cartridge filter. Hayward's support team says it has built them since at least 2004. One large pleated cartridge sits in an injection-molded tank, and the filter head comes off by unscrewing a single locking knob. There's no clamp.

Hayward still sells it in three sizes, all with 2-inch ports: the C9002, C12002 and C17502. Its newer single-cartridge line is the SwimClear, and both are on Hayward's site today.

Which one you have

The number in the model is the filter area. A C900 or C9002 has 90 square feet, a C1200 or C12002 has 120, and a C1750 or C17502 has 175. A 2 on the end means 2-inch ports. Hayward support says that's the only difference between the C12002 and the old C1200, and between the C9002 and the old C900. The C17502 takes the same cartridge as the older C1750, and only its ports changed.

• The C1200 and C900 are finished. Hayward files the C1200 under its discontinued filters, and its support team calls both obsolete.
• The W3C1200 is the exception. It's the 1½-inch 120 sq. ft. filter in Hayward's Open Line, and it's still in Hayward's current StarClear Plus listing.
• A W3 prefix means Open Line. Those are sold online, with one year of parts and no labor. Hayward's 2026 MAP schedule puts the W3C12002 at $879. The C-prefix models come from pool stores and professionals, with three years of parts and a year of labor.
• The tank is black now. Hayward says the taupe version is no longer made, and that the change came from a materials supply problem. It also says the tank has always been injection-molded plastic, never fiberglass.

If you're replacing a 1½-inch filter with a 2-inch one, the plumbing needs reducers. Hayward support told one owner the C9002 doesn't come with adapters, and to buy reducer fittings locally. The 2020 sell sheet says adapters are provided on some models. The manual's parts list also includes a set of two 2-inch PVC socket connectors, CX900K.

Why the 175 isn't faster

Hayward rates residential flow at 1 GPM per square foot, so the C9002 is rated at 90 GPM and the C12002 at 120. The C17502 is also rated at 120 GPM, not 175. Hayward's chart caps the family there.

What the extra area buys is lower resistance, not more flow. The manual's head-loss curve puts one line under the 75, 90 and 120 sq. ft. filters, reaching about 18 feet of head at 120 GPM. The C17502's line reaches about 10 feet at the same flow. Those are my readings off Hayward's curve. So at the same flow, the bigger cartridge puts less load on the pump, and more area generally means longer between cleanings.

For public pools, Hayward's APSP-15 figures use 0.375 GPM per square foot: 34 GPM, 45 GPM and 66 GPM. The 2026 chart recommends 2-inch piping above 90 GPM. The filter sizing guide covers how to match that to your pump.

Installing it

From Hayward's manual:

• Put it on a solid, level surface in a spot that won't flood, as close to the pool as local codes allow, and in shade if you can.
• Leave 18 inches at the side and room above to lift the cartridge out: 19 inches for the 90 sq. ft. size, 25 for the 120 and 30 for the 175.
• Use unions on permanent connections. On threaded ports, use plastic adapters and three turns of Teflon tape. Screw the fitting in hand-tight, then one more full turn with a wrench. The manual warns that more than that can break the filter.
• If the filter sits below the water line, fit valves so water can't flow back into it when it's opened.
• Pick a continuous-duty pool pump. If the pump sits above the water line, it has to be self-priming.

It also wants the filter placed so the tank can drain by gravity.

Starting it

1. Make sure the drain plug is in and closed.
2. Open the manual air relief valve a few turns, and open the suction and return valves.
3. Check the locking knob is secure. Hand-tight is enough.
4. Stand clear of the filter and start the pump.
5. Close the air relief valve when water, not air, comes out of it.

Write down the starting pressure once the flow is steady. That's the number you'll clean against.

The manual's warnings are blunt about pressure. Pool circulation systems run under pressure during start-up, operation and even after shut-off, and the manual says a filter can separate violently if the instructions aren't followed. It says never to run or test the system above 50 psi, and never to purge it with compressed air. For air purging, it allows only a low-pressure blower, under 5 psi.

Cleaning the cartridge

Hayward's trigger is a rise of 7 to 10 psi above the starting pressure, or flow dropping below the rate you want. Hayward support told one C17502 owner that 32 psi was too high for it.

1. Turn off the pump. If the filter is below water level, close the valves.
2. Take out the drain plug and let the tank drain. Opening the air vent a few turns helps. Put the plug back.
3. Unscrew the locking knob counterclockwise and lift off the head.
4. Lift out the cartridge.

Hose it inside and out. Hayward says it's easier to clean when it's dry, and that brushing the pleats after it dries takes off the fine particles. Don't pressure wash it, because that can damage the element. Oils and lotion won't hose off, so soak it in a filter cleaner and rinse it well. The cleaning guide covers the soak.

To put it back, clean any debris out of the bottom of the tank. Slide the cartridge over the tie rod so it sits evenly on the hub at the bottom. Check that the head o-ring is in place and clean, set the head on, and tighten the knob by hand only.

The manual also says vacuuming straight to the filter is fine. Clean the cartridge afterward if it needs it.

The knob that can end it

The locking knob screws down onto a tie rod that's anchored in the bottom of the tank. Tightening it too hard is the one mistake that can finish the filter.

Hayward support told one owner that if the rod has pulled loose from the bottom, the filter has to be replaced. It said the same about a stripped hole in the base: there's no repair. If the rod has only unscrewed from its boss, it can be screwed back in. Support gave the thread as .5625-12 UNC-2A.

Hand-tight is what the manual asks for, and it's all the head needs to seal.

Winterizing

Where it freezes, the manual says to drain the filter completely or take it off the pad and store it indoors. Clean the cartridge and put it back in the tank. When storing it, tighten the knob only a few turns.

Where Hayward's documents disagree

• Warranty. The owner's manual, Rev C, prints a one-year warranty. The product pages and Hayward's 2026 Expert Line terms give three years of parts and one year of labor. The 2026 terms are the newer document, so this page uses them.
• Pressure gauge. The manual lists ECX2712B1. The product page lists ECX271261, and Hayward support gives ECX271261 twice. When an owner's customer care call produced SPX271261, support corrected it to ECX271261.
• The body. The manual lists one body, CX1200AA, for both the C1200 and the C12002, and one, CX900AA, for the C751 and C900, with nothing for the C9002. The ports that differ between old and new models are on the body. If you need a tank, give the dealer your full model number.
• Adapters. The 2020 sell sheet says some models come with adapters. Hayward support said the C9002 doesn't.
• Turnover. Hayward's product pages list turnover in "GPM." The figures are gallons, and they match the chart's gallons.
• Model names. The manual's head-loss curve is labeled "C750." Every other list in the manual says C751.

Replacing it with a SwimClear

Hayward publishes a short guide for swapping a StarClear Plus for a SwimClear. It notes the SwimClear's outlet sits at the same height as the StarClear Plus's, so the outlet union can connect first. It then pipes the pump outlet to the new filter's inlet, with 45-degree fittings recommended.

One difference Hayward support points out: the StarClear filters aren't NSF certified, and the SwimClear filters are.

Parts

The manual's parts list covers every size, with the letter after each reference number marking the size. The knob, knob o-ring, washers, e-ring, guide cone, head o-ring, drain plug and vent valve are shared. The head, body, cartridge, tie rod and air relief tube change with the size, and the 175 has its own knob.

For a C12002, the numbers you're most likely to need are the cartridge (CX1200RE), the head o-ring (CX900F), the gauge (ECX271261) and the drain plug (CX250Z14A). Hayward sells through dealers, not direct.