Pool filters all capture debris, but their media and cleaning routines differ. Cartridge filters trap particles in pleated fabric, sand filters pass water through a bed of sand, and diatomaceous earth (DE) filters use coated grids to catch very fine material. Knowing which system you have helps you choose the right cleaning method, spot problems early, and avoid damaging filter parts. Here’s what to expect from each common type.
Cartridge Filters
A cartridge filter uses one or more pleated elements to catch debris as water flows through. It does not need backwashing. Instead, the cartridge is removed, rinsed with a garden hose, and inspected. Clean between the pleats from top to bottom, taking care not to use a pressure washer, which can tear the fabric or force debris deeper into it.
Clean the cartridge when the pressure gauge rises noticeably above its clean starting pressure, or when flow weakens. If rinsing does not restore flow, an appropriate filter-cleaning solution may help remove oils and residue; follow the product and filter-maker instructions. Replace cartridges with damaged pleats, cracked end caps, or persistent poor performance.
Sand Filters
In a sand filter, water passes through a bed of filter media that catches debris. The usual cleaning method is backwashing: reverse water flow through the filter and send the dirty water to waste. Follow the valve instructions, and run the backwash only as long as needed to clear the sight glass or discharge water, if your system has one. Finish with the specified rinse cycle before returning the valve to filter mode.
Backwash when the pressure rises above the clean baseline or circulation drops, rather than on an arbitrary schedule. Backwashing too often can waste water and may reduce filtration effectiveness. Sand or other media eventually needs replacement, but the interval depends on the media, water conditions, and manufacturer guidance. Never move a multiport valve while the pump is running.
Diatomaceous Earth Filters
DE filters use grids coated with diatomaceous earth powder to capture fine particles. As debris builds up, pressure increases and water flow can fall. Cleaning generally means backwashing the filter, then adding the correct amount of fresh DE through the skimmer as directed by the manufacturer. Backwashing removes used DE along with trapped debris, so the filter needs new powder to work properly.
Some DE filters also need periodic disassembly so the grids can be inspected and thoroughly cleaned. Wear suitable protection when handling DE powder, avoid breathing dust, and follow the product label and local disposal rules. A torn grid or damaged manifold can allow powder to return to the pool; stop and inspect the equipment if you see DE in the water after cleaning.
Choose the Right Cleaning Routine
Start by identifying the filter model and recording its pressure when the filter is clean and the pump is operating normally. Use that reading as your baseline. Check pressure and return flow regularly, and clean when the manufacturer’s threshold is reached or performance changes. Always shut off the pump before opening the filter or changing a valve position, and release trapped pressure before removing a lid.
The key difference is the cleaning method: rinse cartridge elements, backwash sand, and backwash DE filters while replenishing the powder; some systems also require a deeper grid cleaning. Do not mix up procedures or rely on pressure alone if the gauge is faulty. If you are unsure of the filter type, valve settings, or correct DE amount, consult the manual or a pool filter professional.
Each filter type needs a different approach, and the clean-pressure baseline is a useful guide for all three. Match the cleaning method to your equipment, inspect parts for wear, and follow the manufacturer’s instructions. For help identifying a filter or planning maintenance in Sioux Falls, contact Sioux Falls Filter Care.