Sand/Gravels/Pebbles

Filter media is a portion of the filter bed that removes particulate matter from water during the filtration process which includes silica sand, high density sand, gravels, pebbles, anthracite & activated carbon.

It can be used in a wide range of bed depths and particle sizes to produce satisfactory results. Selection of the bed depth or particle size to be used in any particular filter is the responsibility of the designer and should be done with careful consideration of raw water conditions and plant pretreatment facilities. 

In general, for a given pretreatment of raw water and at a given filtration rate, coarse media will permit longer filter runs between washings than fine media. 
With good pretreatment facilities and close technical control, coarse media will yield water of satisfactory quality. With all other conditions fixed, removal of particulate matter is a function of both media size and filter bed depth, and removal generally improves with greater filter depth with smaller media size, or both.

A sand filter is part of a water filtration system whose role is to remove suspended, floating, and sinkable matter from water so that it becomes safe for use.
 A sand filter uses sand to filter water through the process of sand filtration. The water slowly sinks through the sand of the sand filter, leaving the dirt particles from the water behind in the fine pores of the sand. A Sand Filter includes a multiport valve and an FRP Vessel.

Gravels Pebbles:
Filter Gravel is an extremely effective filter media because of its ability to hold back precipitates containing impurities. Filter sand size, angularity, and hardness are important filter sand characteristics to ensure proper filtering. Products meet or exceed the NSF/ANSI Standard 61 for Drinking Water System Components, as well as AWWA Standard B100-01. 

Function of Gravel
We use gravel, along with sand, in the production of concrete, as well as for asphalt mixing. We can use gravel in the filtration of water, where it acts as a natural filter holding back precipitates that may contain impurities as well as other sand-sized particles. The angularity and hardness of gravel make it resistant to water erosion.

Is Gravel an Effective Filter?
Gravel is better than nothing, but it’s no substitute for sponge or ceramic media with internal pore spaces, such as sponge or lava rock. Long ago, gravel was employed in some pond filters, but lighter, simpler-to-clean materials with more useable pore spaces became available. Filter Gravel is an extremely effective filter media because of its ability to hold back precipitates containing impurities. Filter sand size, angularity, and hardness are the important filter sand characteristics to ensure proper filtering.