Pool filter types and replacement: identify what you have.
Compare sand, cartridge, and D.E. pool filters. Find the model, match replacement media, and interpret pressure against your own clean-system baseline.
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Identify the filter before shopping
Read the label on the filter tank, not just the pump. Sand, cartridge, and diatomaceous-earth (D.E.) filters use different media and maintenance procedures. A similar tank shape or the same brand does not prove that replacement parts fit.
Photograph the model label and record the serial number or revision if present. Use the manufacturer’s parts diagram to distinguish a single element, a set of elements, a grid assembly, and a complete filter.
Three filter families
A specified bed of filter media
Required media type, grade, and quantity for the exact tank. Pool-filter sand is not ordinary play sand.
Pleated elements inside a housing
Part number, element count, length, outside diameter, and end-cap/opening design.
D.E. media supported by internal grids or elements
Specified media, recharge amount and method, and the exact grid or element assembly.
Build a replacement-part checklist
Do not use the pump motor’s label as the filter model. Save a readable photograph of the tank label.
Locate the element or assembly in the manual. Check model suffixes, production revisions, and whether multiple sizes share the same family name.
A listing may supply one cartridge, a complete set, an individual grid, or the whole assembly. Compare what the system requires with what the box contains.
Use dimensions as a second check after the documented part relation. Two elements with similar length and diameter can differ in openings or end caps.
Retain the part number and compatibility evidence. If the listing contradicts the manual, resolve that discrepancy before ordering.
Use the clean pressure as your reference
Record pressure after correct cleaning or service, at the normal pump speed and valve configuration. Compare future readings under those same settings. A filter reading 20 psi is not automatically dirty; it might be normal for one installation and abnormal for another.
Use the cleaning threshold in the exact manual. Do not apply a universal absolute pressure or assume every filter uses the same increase above baseline. If your baseline was never recorded, arrange a proper service and establish it.
Low pressure and poor flow can point to a different issue from a dirty filter. Avoid buying a new cartridge solely because a gauge number looks unusual. Record changes in flow, noise, and recent equipment work.
Replacing media is different from replacing the filter
A cartridge with confirmed damage or one that no longer performs after appropriate cleaning may need replacement; a tank, clamp, or seal fault is a separate repair. Inspect and service according to the manufacturer’s requirements rather than using age alone as a replacement rule.
For sand filters, confirm the prescribed media specification and quantity before ordering. Do not substitute an alternative medium simply because its bag mentions pool filtration. For D.E. systems, the charge following backwash may differ from a full new charge; use the model procedure.
When replacing an entire filter, verify design flow, plumbing connections, installation space, valve arrangement, and service access. Pool volume by itself does not establish the right filter size.
Respect pressure-vessel service limits
Pentair recommends professional filter maintenance. Other manufacturers’ equipment must be serviced under their own instructions. If the manual is missing, a clamp is damaged, the body leaks, or the pressure cannot be safely relieved, arrange qualified service. This page identifies parts; it is not a tank-disassembly procedure.
Common questions
Can I buy by pool gallons alone?
No. Whole-filter selection needs flow and installation requirements. Replacement media needs the existing filter model and documented specification.
Is one replacement cartridge enough?
Check the manual and listing. Some filters use several elements; the merchant may be selling only one.
Does high pressure mean I need a new filter?
Not necessarily. Compare with the clean baseline and investigate using the manual before replacing equipment.
Sources and product instructions
The references below support the technical checks in this guide. Use the instructions for your exact product or local conditions when they differ from a general example.