Which Hayward DE Grid Do I Need? Identifying Pro-Grid and Micro-Clear Grids by Filter Model, Plus Perflex Elements

Diatomaceous earth showing up in the pool is the DE filter's one unambiguous complaint. Everything else it does — creeping pressure, short cycles, a cloudy pool that will not clear — has three or four possible explanations. A white plume from the returns on start-up has exactly one meaning: somewhere between the filter's dirty side and its clean side there is a hole, and DE is going through it.

Finding the hole is the first half of the job. The second half is ordering the right grid, and that is where most of the frustration lives. Hayward has sold vertical-grid DE filters under two names (Micro-Clear, then Pro-Grid) across five sizes, and the grid sets have carried two generations of part numbers. The good news is that the grids identify themselves: if you know the filter's square footage, you know the grid height, and if you know the grid height, you know the set. This guide lays that out, then walks through the parts around the grids that fail with them.

Reading the symptoms

DE in the pool. A puff of white powder from the returns when the pump starts, DE settling on the floor near the returns, or a fine grey-white ring in the skimmer throat. This is bypass, and it is always one of four things: a torn grid, a cracked top manifold, a split or badly seated standpipe o-ring at the bottom of the assembly, or a backwash-valve gasket letting filtered and unfiltered water mix. Over-dosing DE after a backwash mimics it — the excess simply passes through until the cake forms — so before condemning anything ask how much was added. The service literature calls for roughly 80% of the full charge after a backwash, not the full charge.

Pressure that climbs too fast. A clean, freshly charged DE filter should run for weeks before it reaches its backwash pressure. If it gets there in days, the grids are either coated in something backwashing does not remove (oils, sunscreen, calcium) or the fabric has blinded permanently. That is a cleaning call first, a replacement call second.

Pressure that never comes up, and a pool that will not clear. The opposite problem: water is finding a path around the cake. Same four causes as DE in the pool, just without enough DE escaping to be obvious.

Short cycles combined with a wobbling pressure needle. Usually air, not grids — a suction-side leak that lets the filter back-drain when the pump stops. It matters here because a back-draining filter also dumps DE into the pool, and it will do so again after you have replaced a perfectly good grid set.

Prep and safety

Power off at the breaker. Relieve pressure at the air relief valve until the gauge reads zero. If the equipment pad sits below water level, close the suction and return isolation valves. Open the drain plug and let the tank empty; a 72 square foot tank holds a lot of water and a lot of wet DE, and the clamp ring should never come off a tank under pressure or full to the top.

Loosen the clamp evenly. On Pro-Grid tanks the clamp is a two-piece band with a nut and bolt; if the hardware is corroded, or the band has been over-torqued and stretched, replace it rather than re-using it — it is the only thing holding the two halves of a pressure vessel together. The DEX2421JKIT clamp and seal kit includes the band, hardware, tank o-ring and manual air relief assembly; the DEX2421J2 nut and bolt covers the hardware alone.

Identifying the grid set

Hayward's vertical-grid filters use eight grids per tank: seven full grids and one partial grid, the partial one leaving room for the standpipe. All five sizes share the same top manifold and the same bottom element locator; what changes with tank size is the height of the grids and the length of the retainer rod that holds the assembly together. So the identification question is really "how tall are the grids", and the model plate on the tank answers it.

Grid heights and rod lengths are as published in Hayward's Pro-Grid parts literature and confirmed against two independent distributor listings; tank dimensions for the five models run from about 32½ to 52½ inches tall at a constant 24-inch diameter, so the model number is usually on the tank but the grid height is the fastest cross-check when the plate is gone.

Two things to notice in the table. First, the "DE2400 / DE3600 / DE4800 / DE6000 / DE7200" numbers are the older Micro-Clear tanks; the "…20" numbers are the current Pro-Grid tanks. The grids are interchangeable across the two generations of the same size — a 48 square foot Micro-Clear takes the same 24-inch grid set as a 48 square foot Pro-Grid. Second, Hayward's own set numbers changed at the same time (DEX4800DC became the number for the DE4820's set, and so on). Our DEX4820DC and DEX7220DC sets are cross-referenced to both writings so that a service company working from an old invoice or a new one lands on the same part.

Hayward sells the grids for each size as a complete cluster — eight grids on the manifold with locator, rod and breather tube — and a grid element set is how we recommend replacing them too; confirm what is included in the set you order, since sets are also sold as grids only. Grids in one tank are the same age and have seen the same water; when one fabric tears, the others are usually a season or two behind it, and a mixed set of new and tired grids loads unevenly — the new ones take the flow and blind first.

The parts around the grids

The grid fabric is the wear item, but three other parts in the assembly fail often enough to be inspected every time the tank is open, and two of them are the actual cause of DE bypass more often than the grids are.

Top collector manifold, DEX2400C. Eight sockets on the underside accept the grid necks; the centre port takes the standpipe; the small port on top takes the flex air relief tube. It cracks in two places — at the socket walls, from years of grids being pushed in and pulled out, and around the standpipe connection, typically from water hammer when a return-side valve is closed against a running pump. A hairline crack at a socket lets unfiltered water straight into the clean side and is invisible with the grids installed. Take the grids off and look at each socket against the light. The manifold is common to all five sizes.

Element locator, DEX2400H. The plastic plate at the bottom of the assembly that holds the grid feet in position. A broken finger on the locator lets a grid shift, and a shifted grid rubs its fabric against its neighbour until it wears through — so a torn grid with a worn patch on one face, rather than a puncture, points to the locator, not to the grid. Common to all five sizes.

Retainer rod. Runs from the locator up through the manifold and clamps the assembly together. Rods bend when the assembly is dropped or forced, and a bent rod holds the manifold cocked so that one or two grids never seat fully — another source of bypass that looks like a bad grid. The rod is the one size-specific part besides the grids themselves: DEX2400R for the 24 square foot tank, DEX6000R for the 60, DEX7200R for the 72.

Tank o-ring and standpipe seat. The tank o-ring sits in the groove between the two halves; the standpipe seals into the bulkhead at the bottom of the tank. Either one, worn or pinched, bypasses DE. The tank o-ring is in the DEX2421JKIT; inspect the standpipe o-ring every time the assembly comes out, and lubricate both with a pool-grade silicone lubricant on reassembly, not petroleum jelly.

Grids: clean, or replace?

Take each grid off the manifold and hold it up to the light. Replace the set if you find any of these:

• A tear or a hole, however small. Fabric does not heal and does not patch.
• Fabric lifting from the frame along an edge or at the neck. The bond has failed; the next backwash finishes it.
• A broken or bowed frame rib under the fabric. The rib will wear a hole from the inside.
• A worn patch on one face — the sign of a grid rubbing against its neighbour; check the locator and rod before fitting new grids or the new ones will wear the same way.
• Fabric that stays grey or yellow after a full clean. Oils and calcium that survive a degreaser soak and an acid rinse have permanently reduced the open area. The pressure history tells you the same thing: short cycles that a thorough cleaning does not fix.

If the grids pass all five, clean them rather than replace them: hose off the DE, soak in a filter-cleaning degreaser, rinse, and in hard-water areas follow with a dilute muriatic acid rinse to lift calcium — never mixing or reversing the order of the two solutions. Grids that are cleaned properly once or twice a season are the ones that reach the seven-to-ten-year life the fabric is capable of; grids that only ever see a backwash are the ones replaced at four.

Perflex is a different filter

A word on the third Hayward DE family, because the search that led you here may have been for it. The Perflex EC series (EC30, EC40, EC40AC, EC50, EC65, EC75) is a horizontal-tube "bump" filter, not a vertical-grid filter. It has no grid set, no top manifold and no retainer rod. Its filter element is a single cluster of flexible tubes — CX5000BP for the EC40AC and EC50AC — and its wear items are the diaphragm gasket and bump shaft that regenerate the DE cake. We have covered that mechanism and its rebuild in a separate guide: Hayward Perflex DE filter: how the bump mechanism works and how to rebuild it. The Perflex model page lists everything that fits it.

And one more source of confusion: the SwimClear (C2030, C3030, C4030, C5030, C7030) is a cartridge filter, not DE. It shares the Pro-Grid tank clamp — which is why the DEX2421JKIT fits it — but it has cartridges and a cartridge manifold (CX3030C, CX5030C), no grids. If your filter is a SwimClear and there is powder in the pool, it is not DE and the problem is elsewhere.

Reassembly notes

1. Fit the new standpipe o-ring, lubricated, and seat the standpipe fully in the bulkhead before lowering the assembly in. A standpipe that is proud by a few millimetres will crack the manifold when the tank halves are drawn together.
2. Set the assembly so the partial grid sits over the inlet side as the original did; the partial grid's job is to clear the standpipe, and it only does that in one orientation.
3. Connect the flex air relief tube from the manifold to the air relief on the tank lid. A disconnected tube leaves an air pocket in the top of the tank that reduces the working grid area and shows up as a pressure gauge that reads high with no flow to justify it.
4. Clean the tank o-ring groove, fit the lubricated o-ring, and draw the clamp down evenly, tapping the band around its circumference as you tighten so it seats uniformly. Torque per Hayward's instructions for the clamp — not "as tight as it will go".
5. Start the pump with the air relief open, let it prime, close the relief when water sprays, then add the DE charge through the skimmer with the pump running. Note the clean starting pressure on the tank; that number is the baseline every future symptom is judged against.

Cross-reference table

The complete list of parts that fit each tank is on the model pages: Pro-Grid, DE3620, DE4820, DE6020, and for the bump filters Perflex and EC40AC. All DE grids and elements across brands are under DE Grids & Elements.

Sourcing

POOLPOINT manufactures DE grid element sets, manifolds, locators, retainer rods and clamp kits factory direct for US distributors, service companies and online sellers. Grid fabric is polypropylene on a rigid frame, dimensioned against the OEM grid for each tank size. MOQ starts at 50 pieces per SKU, with mixed cartons accepted to reach it and private label available. Request a quote for wholesale pricing.