Sand, cartridge, or DE — every filter type has a different maintenance routine and a different price tag. This hub explains how filtration actually works and helps you size and choose the right filter for your pool.
What You’ll Find In This Guide
- Sand vs cartridge vs DE filters compared
- How to size a filter correctly
- Backwashing and cleaning routines
- Signs your filter needs attention
Types at a Glance
| Filter Type | Maintenance | Filtration Fineness |
|---|---|---|
| Sand | Backwash periodically | Good — down to ~20 microns |
| Cartridge | Rinse/replace cartridge | Better — down to ~10-15 microns |
| DE (diatomaceous earth) | Backwash + recharge with DE powder | Finest — down to ~5 microns |
Frequently Asked Questions
What does “backwashing” a pool mean?
Backwashing reverses the normal water flow through a sand or DE filter to flush trapped debris out to waste, cleaning the filter media without having to open and manually clean it.
Where does backwash water go?
It’s usually directed to a designated waste line, garden/drainage area, or sewer connection depending on your council’s rules — check local regulations, since backwash water is chemically treated pool water, not greywater.
How often should I change my pool filter?
Cartridge filters are typically rinsed regularly and replaced roughly every 1-2 years depending on use and water quality; sand media is generally replaced every 5-7 years as it loses filtering effectiveness.
How much do pool filters cost?
Cost depends on filter type and size — cartridge units tend to have a lower upfront cost with more frequent consumable replacement, while sand and DE systems cost more upfront but have cheaper ongoing media.
How does a sand filter work?
Water is pushed down through a bed of specially graded sand inside a pressurised tank; dirt and debris get trapped in the sand bed while clean water passes through and returns to the pool.
Guides in This Category
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