Pentair Pool Filter Parts: Numbers, Fit, and Costs

Pentair filters hold up well, which is exactly why so many pool owners end up shopping for a single part instead of a whole new tank. A weeping seam, sand at the return jets, or a gauge stuck at zero is almost never a reason to replace a working Clean and Clear or Triton II. The obstacle is finding the right part number, because Pentair sells several filter families, each with its own internals, and the parts that look generic often are not.

This page is Pentair specific: which parts belong to which family, the numbers people actually search for, where these filters tend to fail, and rough costs. If you want the plain explanation of what a spider gasket or lateral does regardless of brand, the general pool filter parts guide covers that ground. For care and cleaning of the filter itself, see the Pentair pool filter guide.

How Do You Find the Right Pentair Filter Part?

Start at the label on the tank body. The model name and number printed there, for example Clean and Clear Plus 320 or Triton II TR60, is what drives every part you order. Pentair publishes exploded parts diagrams for each model in the owner’s manual and its parts catalogs, with every component numbered, so once you have the model number you can point at the piece in your hand and read off its number. Sta-Rite diagrams are worth checking too, because Pentair owns Sta-Rite and a fair number of seals, gauges, and valve components cross over between the two catalogs.

Three habits make this reliable:

1. Photograph the tank label before you start taking anything apart. It fades, and it is often on the underside curve of the tank where you cannot read it once the housing is full of water.
2. Order by diagram number, not by description. Searching “Pentair tank o-ring” returns a dozen sizes. Searching your model number plus the diagram number returns one.
3. Keep the old part. Comparing the new seal against the old one on the bench takes ten seconds and prevents a second trip.

Pentair Parts by Model Family

The three families below cover most residential Pentair filters in service. Part numbers listed are the ones most commonly published for these models and should be treated as a starting point, not a guarantee of fit.

Confirm every number against your own manual or the parts diagram for your exact model and production year before ordering. Pentair has revised tank designs, clamp bands, and o-ring sizes across generations of the same product name, and a part that fits a current Clean and Clear Plus may not fit a tank from a decade earlier.

Pentair 87300400: The O-Ring People Search For

This number gets searched more than almost any other Pentair part, and the reason is simple: it is the one thing standing between a pressurized tank and your pool pad.

87300400 is generally listed as the tank body o-ring, the large ring that seals the upper tank half to the lower tank half on Clean and Clear cartridge housings and several similar Pentair tanks that use a clamp band rather than a threaded lid ring. It does not filter anything. It only seals, and it is under load every second the pump runs.

You know it has failed when water weeps or sprays from the seam right at the clamp band while the system is pressurized. The drip is usually slow at first and shows up as a wet ring on the pad under the filter, then gets worse as the rubber flattens further. A failing tank o-ring can also let air in on the suction side of some setups, so persistent air in the tank after bleeding is a secondary clue. The full diagnostic sequence is in our guide to why a pool filter is leaking.

Two rules when you install the replacement. First, seat the o-ring fully in its groove and check the entire circumference before you bring the clamp band down, because a ring that is pinched or twisted in one spot will leak from that exact spot within a week. Second, lubricate it with a silicone based pool lubricant only. Petroleum jelly and petroleum greases swell rubber and shorten seal life, and they are the single most common reason a brand new o-ring fails in one season.

Shop Pentair 87300400 o-rings on Amazon

If you are ordering the seal anyway, add a tube of pool filter silicone lubricant to the same order. It costs a few dollars, it is the correct product for every o-ring on the filter, and having it on the shelf is what makes the yearly re-lube actually happen.

The Pentair Parts That Fail Most

• Spider gasket (Triton II and any Pentair multiport valve) is the flat spoked gasket inside the valve, and when it wears you get water trickling continuously out the backwash or waste line while the valve is set to filter. Symptoms and the teardown are covered in pool filter multiport valve problems.
• Tank body o-ring flattens, dries, and cracks, then weeps at the clamp band or lid seam. It is the cheapest failure on the filter and the one most often ignored until the pad is soaked.
• Pressure gauge dies quietly. A gauge stuck at zero, pinned high, or frozen at one reading no matter what the system does is a dead gauge, not a dead filter; the test sequence is in pool filter pressure gauge not working.
• Laterals on Triton II sand filters crack with age or from a dry startup, and a single split lateral pushes sand back into the pool through the return jets. See why a pool filter is blowing sand before you pull the sand out.
• DE grids on FNS Plus filters tear along the seams or where the fabric rubs the manifold, and the giveaway is a gray plume of DE powder at the jets after you recharge the filter.

For the actual repair procedures once you have identified the failed part, the pool filter repair guide walks through each one.

Pentair Part Costs

Prices move, and OEM parts usually sit at the top of these ranges while compatible aftermarket parts sit at the bottom. Treat these as ballpark figures:

The pattern is the same one that holds across every brand: four of the five most common Pentair failures cost less than 90 dollars to fix. Only a full DE grid set is expensive enough to be worth weighing against a new filter, and even then a torn grid can often be replaced individually rather than as a set.

A cheap insurance policy here is a matched pool filter o-ring kit for your model, which replaces the tank seal, drain cap seal, and union seals in one pass instead of chasing drips one at a time. Do the swap while the tank is already open for a cleaning, which is covered step by step in cleaning a Pentair pool filter.

Sta-Rite Parts Cross Over

Pentair acquired Sta-Rite in 2004 and still builds and supports the System 3, Posi-Flo, and Cristal-Flo lines under the Sta-Rite name. Because both brands sit under one parent with shared suppliers, a number of components interchange: o-rings, pressure gauges, drain caps, air relief assemblies, and several multiport valve internals frequently appear in both catalogs under different numbers for what is physically the same part.

Where the crossover stops is anything structural. Cartridge elements, System 3 modules, laterals, DE grids, and manifolds are dimensioned for their specific tank and should be matched to the model on your label, not to the brand on the sticker. If your pad has a Sta-Rite tank on it, the Sta-Rite pool filter guide covers that lineup and its own part numbering.

Related Guides

• Pentair Pool Filter Guide - the full Pentair lineup, sizing, and ownership notes
• Pool Filter Parts - what each filter part does, across all brands and filter types
• Cleaning a Pentair Pool Filter - teardown and cleaning procedure by Pentair family
• Sta-Rite Pool Filter Guide - the Pentair owned sister brand and its parts
• Pool Filter Repair - fixing leaks, cracks, and failed parts once you know the culprit
• Why Is My Pool Filter Leaking - tracing a leak to the o-ring, clamp band, or union