Sand Filter
A filter using silica sand to trap particles down to 20–40 microns.
Definition
Sand filters use a bed of specially graded silica sand (#20 grade) to capture suspended particles. Water flows down through the sand, which traps debris, algae, and fine particles. When the filter pressure increases 8–10 psi above the clean baseline, the filter needs backwashing — reversing the flow to flush trapped material to waste. Sand should be replaced every 5–7 years. Sand filters have the coarsest filtration (20–40 microns) of the three main filter types but are the lowest maintenance.
Relationships
Outgoing Relationships
- part of → Filtration
- compared with → Cartridge Filter
- compared with → DE Filter
- requires → Backwashing
Incoming Relationships
- uses ← Filtration
- maintained by ← Backwashing
- compared with ← Cartridge Filter
- compared with ← DE Filter