Understanding Sand Media Filtration
Media Filtration is the most effective method for removal of suspended organic and inorganic solids from water. The media filters operate on the same basic principle as nature’s own ground water filtering process. Contaminated, unfiltered water enters the system through a deflector in the top of the filter and flows, under pressure, through the media where solid particulate is entrapped.

Media filters are known for their capacity to extract and hold large amounts of water-borne particulate while continuing to deliver a rated flow of clean water.

In addition to the water filter’s ability to filter large volumes of water with very little pressure drop, one of the outstanding features is the simple backwash operation. This excellent cleaning process is possible due to the highly efficient underdrain systems utilized in media filters.

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Sand media filtration for home or commercial application:
The single tower is whereby you only have one sand filter and believe me, no matter how people say this single tower is very good, there actually don’t know how bad this system is until they open their water storage tank above after 1 year. If they install a transparent filter after the sand filter, the transparent filter will turn black after 1 week. This shows particles can still pass through the sand filter. As for backwashing, only 60% of the dirt will be able to flush out as it is very difficult for the normal water pressure to push the sand up and out to the drainage system again once it is deep inside the sand. Particles which still in the sand will oxidize and form a soft layer of mud or even stone which reduce the pressure of your water and enable the dirt to pass through inside your house.

Another type of sand filter model is The Twin Tower. This is the best among all the sand filters in term of filtration quality. Twin Tower series is the combo combination of 2 unit of frp sand filter with bullet type tank/ housing. This system is very effective for your house or factory. Sand filter is around 10-15 micron. The first filter is with 5 layer of sand media with zeolite, activated carbon, fine silica sand, medium silica sand and gravel. The second filter consist of 3 layers of sand media mainly the fine silica sand, medium silica sand and gravel. The reason of 2 system is because the particles and sediments that passes through the first filter will be able to filtered out in the second system. The result is not only crystal clear water, infact if you have an indoor filter (purifier), the internal filter will even last longer.

Another advantages is during backwashing of the system,the second filter is flushed by filtered clean water from the first filter. Therefore the 2nd filter is very clean and the water that goes to the storage tank will be very well filtered. If you have experiment with a normal 10inches sediment transparent filter housing, you will see the first filter become dirty very fast, if you install a second one after the first one, the second filter will also become dirty but lesser, if you install a third one, the third one will become very clean even though after sometime. This prove that by having 2 system, water will be very well filtered out. Disadvantage of this system is the maintenace and also the space taken by this system. It use up alot of water for backwashing and as said earlier, only 60% of the dirt will be able to flush out as it is very difficult for the normal water pressure to push the sand up and out to the drainage system again once it is deep inside the sand. Particles which still in the the sand will oxidise and form a soft layer of mud or even stone which reduce the pressure of your water and enable the dirt to pass through inside your house.

Sand medias need to be replaced about 3-5 years. Some will even tell you don’t have to change your filter sand forever which is not true and want to portray that their system has lesser maintenance. Even though the sand will not get faulty even after years of usage, the media in the filtration vessel will become extremely dirty and hardened due to the amount of dirt trapped inside it. Moreover the back washing cannot 100% flushed out the particles or sediments in between it.

Therefore the accumulation of dirt and particles can cause this tank as a bacteria breeding tank and also possibility lowered the water pressure.

For more information about sand or media filtration system, please email to us on
info@waterexpress.com.my or call us at 03-5621 7915