Parts of a Sta-Rite Crystal Flo Sand Filter

Special Sand Used

• The Sta-Rite Crystal Flo filter uses sand to trap contaminants as water flows through the unit. A specialized silica sand with grains about a ½ millimeter in diameter is specified. The Sta-Rite Manual warns that "use of other sands will reduce filter performance, may damage pump, and will void warranty".

Filter Tank

• The sand is poured into the filter tank. The tank is offered in sizes ranging from 600-pounds sand capacity with the T-300-BP2 model filter to 100 pounds with the T-150BP-1 filter. The silica sand is sifted through a plastic "loading disc" as it is added to the filter tank to keep it pure. The filter tank has an O-ring at the top where the valve body mates to it to contain the system pressure. The filter tank rests atop a pedestal for a stable platform.

Multi-Port Valve

• The multi-port valve clamps into the top of the filter tank with a snap ring which is called a V-clamp in the Sta-Rite manual. Hoses are attached to the valve which route water to the pool, filter tank, and drain. The valve controls the flow of water and can be adjusted to perform filtration, draining, or back-flush operations. Back-flushing is a necessary maintenance operation to keep the filter working properly.

Laterals and Hub

• There are 8 lateral extensions radially attached to a vertical PVC pipe called the hub which extends to the bottom of the filter tank. Water flows from the control valve into the tank, and the sand media traps contaminants while the water flows into the laterals and hub. The water flows upward through the hub and into the multi-port valve is it exists the filter tank. The water flow can be reversed by moving the multi-port valve to the back-flush position. The flush water is sent into the municipal drain during back-flushing.

Filter Tank Drain

• A drain cap and O-ring secure to the bottom of the filter tank for easy water removal. A small threaded rod, called a drain lateral, extends inside the filter tank. It allows water to escape through the drain port, but keeps the sand from escaping.