Sand is the oldest and most popular method of filtration. Sand filters share two things in common:
- When in the filtration mode, water always flows from top to bottom
- They all have some sort of lateral or underdrain with slots to hold back sand while allowing clean, filtered water to pass through.
High-rate sand filters use a special filter sand, normally .45 to .55 mm (also known as pool grade #20 silica sand), because it has sharp edges that separate particles, allowing filtration to take place. They operate on the basis of depth filtration where dirt is driven through the sand bed and trapped in the spaces between the sand particles. Initially, a clean sand bed removes larger particles, and then, as the bed starts to load up with debris, the filter removes finer particles. The sand can be cleaned by backwashing which involves reversing water flow through the filter to the waste line. Sand filters trap debris as small as 20 to 40 microns.
Pro Series high-rate sand filters are the very latest in pool filter technology. Molded of durable, corrosion-proof reinforced thermoplastic, Pro Series filters feature an advanced, self-cleaning lateral under drain system for smooth, efficient flow and totally balanced backwashing.Pro Series sand filters also feature a self-cleaning 360-degree slotted lateral for totally balanced flow and backwashing. Their integral top diffuser ensures even distribution of water over the top of sand media bed with full size internal piping for smooth, free-flowing performance. So for crystal clear water with only minimal care, pool professionals choose Pro Series.
Features
- Top diffuser ensures even distribution of water over the top of the sand media bed. All internal piping is to give smooth, free-flowing performance
- Manual air relief purges any trapped air during operation of the filter system
- Unitized, corrosion-proof, filter tank molded of rugged, colorfast reinforced thermoplastic dependable, all weather performance
- 6-position Hayward Vari-Flo control valve with easy-to-use lever-action handle lets you dial any of the 6-valve/filter functions. Integral sight glass lets you see when backwash cycle is completed
- Precision-engineered umbrella-fold self cleaning laterals for balanced flow and backwashing, plus easy serviceability
- Large pressure sand/water drain for rapid winterizing or servicing