Sand filter sand cylinder using tiny dirt pool eliminated. As remove dirt sand filtration media is loaded in the filter cavity. When the control knob to open, the water contains suspended particles of dirt from the pump into the filter device, and then by the guidance control switch reaches the filter outlet. Water passes through the filter, the tiny dirt is filtered out sand bed filtration. The filtered water from the bottom of the filter and then returned to the pool through the pipeline control switch. Advantages: 1. reinforced polyester seamless casing, glass fiber wound spherical structure makes Sand firmer surface through non-toxic treatment. 2. Anti-corrosion, abrasion resistance, UV UV, anti-oxidation. 3. Unique flow water distribution and water catchment form balanced, high-efficiency drainage culvert. 4. Filter high precision, good water quality, turbidity <20um. 5. The high filtration velocity, filtration rate of up to 10 ~ 50m3 / h / m2. 6. A multi-directional valve operation easy and convenient, a transparent wash water outfall to observe the extent clear. 7. with a barometer, a manual vent valve and drain valve. 8. bolts, nuts and fasteners are made of stainless steel. 9. Clean fast filter is not lost, easy operation and maintenance.