Multi-Media Sand Filters

Directions: The flow rate that can be achieved through Multi-Media Sand Filters is dependent on the surface area of the filter. The larger the diameter of the filter tank, the more water it can process in gallons per minute (“GPM”). However, a larger diameter tank also requires a higher backwash flow rate, in order properly backwash and expand the filter media.

To find out the flow rate and backwash flow rate for a given tank size, and how much media you will need, enter the values in boxes 1, 2 and 3, and then press Calculate.

What flow rates should be used?

Multi-Media Sand Filters can process water at rate of 5 to 12 gallons per minute, per square foot of filter surface area. For best results use the figure 5 gallons per minute.

For backwash flow rate, a flow rate of 13 to 18 gallons per minute, per square foot is recommended. At 60F temperature or less, 13 GPM per square foot will work well, but if the water is warmer than 60F then 18 GPM is recommended.

Directions: The flow rate that can be achieved through Multi-Media Sand Filters is dependent on the surface area of the filter. The larger the diameter of the filter tank, the more water it can process in gallons per minute (“GPM”). However, a larger diameter tank also requires a higher backwash flow rate, in order to properly backwash and expand the filter media.

Enter Filter Flow Rate Per Square Foot of Media Gallons Per Minute
Enter Backwash Flow Rate Per Square Foot Gallons Per Minute
Enter Tank Diameter in Inches

Square Feet of Filter Media
Flow Rate in Gallons Per Minute
Backwash Flow Rate in Gallons Per Minute

Lbs of Media Gravel 8-12 Garnet Fine Garnet Anthracite TOTAL
Cubic Ft Media
Bed Depth 4 8 10 14 36 inches

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  • Clean Water Systems & Stores, Inc., Water Treatment Equipment,Service & Supplies, Santa Cruz, CA