Hayward ProSeries Sand Filter Inground 21 In Top Mount 1.5 Inch Valve

Hayward ProSeries W3S210T 21-Inch Top-Mount Sand Filter for In-Ground Pools

The Hayward ProSeries W3S210T is a 21-inch top-mount sand filter for in-ground pools. At 2.20 sq ft of filtration area and a 44 GPM design flow rate, it handles mid-size residential in-ground pools and delivers 20-40 micron sand filtration with a simple backwash-based maintenance routine. The 7-position 1.5" Vari-Flo valve ships installed and ready to plumb; the flange clamp allows 360-degree valve rotation to simplify alignment with existing piping.

Sand filtration requires no cartridge replacements and no D.E. media handling. A 2 to 3-minute backwash cycle restores the filter bed when pressure climbs 8 to 10 PSI above baseline, and the same 200 lbs of #20 silica sand typically lasts 3 to 5 years. If you need the same filter paired with a side-mount valve, the W3S210S is the side-mount equivalent.

Hayward W3S210T ProSeries 21-Inch Sand Filter Key Features

• 7-position 1.5" Vari-Flo top-mount valve - Filter, Backwash, Rinse, Waste, Recirculate, Closed, and Winter positions. Integral sight glass confirms backwash cycle completion. Flange clamp allows 360-degree rotation.
• Integral top diffuser - Distributes incoming water evenly across the full sand bed surface, maximizing use of the entire filtration area.
• Umbrella-fold self-cleaning laterals - Full 360-degree slotted laterals provide energy-efficient flow and evenly balanced backwashing across the full base of the tank.
• Full-size internal piping - Smooth, free-flowing performance with minimal head loss through the filter body.
• Large pressure sand/water drain - Full-size base drain for fast winterizing or sand changes without tilting the tank.
• Corrosion-proof reinforced thermoplastic tank - UV-stable, all-weather construction rated for permanent outdoor in-ground pool installations.

Hayward W3S210T ProSeries 21-Inch Sand Filter Specifications

Sand not included. Use #20 grade silica pool filter sand only. Pool coverage depends on pump output at actual system head and turnover rate targets.

Hayward ProSeries In-Ground Sand Filter Lineup: W3S210T in Context

The W3S210T is the entry-level in-ground model in this ProSeries lineup. Stepping up in tank size increases filtration area, sand capacity, and flow ceiling. Note that the W3S310S ships without a valve; a compatible backwash valve must be purchased separately for that model.

Flow rates and filtration areas per Hayward published specifications. Pool size coverage depends on pump sizing, turnover rate targets, and site conditions.

Maintaining the Hayward W3S210T ProSeries 21-Inch Sand Filter

Record the clean baseline pressure at first startup after loading sand. Backwash when pressure climbs 8 to 10 PSI above that baseline. Switch to Backwash, run until the sight glass clears, Rinse for 15 to 30 seconds, then return to Filter. Sand typically lasts 3 to 5 years. Signs it needs replacing: persistent cloudiness after correct backwashing, fine sand appearing at return fittings, or very short intervals between backwash cycles.

First Startup: Loading Sand

Fill the tank halfway with water before adding sand to protect the lateral assembly. Add 200 lbs of #20 silica sand gradually. Run a full Rinse cycle before switching to Filter to flush fine dust from the new media. Note the post-Rinse pressure as the clean baseline.

Winterizing the W3S210T

Backwash before shutdown. Drain the tank fully through the base drain and leave the plug out for the off-season. Set the valve to the Winter position to drain the valve body and prevent freezing in the valve passages. In hard-freeze climates, blow out the valve with compressed air for additional protection.

Hayward W3S210T ProSeries 21-Inch Sand Filter Frequently Asked Questions

Hayward W3S210T ProSeries Sand Filter Documentation