Sand filters come in the range of 20 to 40 microns. The method is probably the oldest and the most popular method of filtration ever used. Sand filters use a special filter sand, which is also known as pool-grade, #20 silica sand and normally .45 to .55 mm. The material is known to have sharp edges that serve to separate particles. This in turn allows filtration to take place. Sand filters are the least expensive of the three types of filters generally used, but they only filter particles up to 20 to 40 microns in size.
A number of things could be causing the problem in your sand filter and you need to first identify the problem. It could involve a lateral that is cracked or broken or even a valve that may need servicing. Air could be passing through the filter, causing a channeling effect that permits dirt to get by. In the latter, there may actually be nothing wrong with the filter.
However, to replace the sand in the filter, you need to first disconnect the pipes going into the valve on top of the filter. Then you need to unscrew the complete valve and once the valve has been removed, you will be able to access the sand bed. The best way to remove the sand is to either use a portable vacuum or just tip the contents into a small container. Then clean and fill the tank 2/3 full of water and just pour in the new sand. Avoid sand entering the vertical pipe that protrudes from the bottom of the filter tank.
A number of things could be causing the problem in your sand filter and you need to first identify the problem. It could involve a lateral that is cracked or broken or even a valve that may need servicing. Air could be passing through the filter, causing a channeling effect that permits dirt to get by. In the latter, there may actually be nothing wrong with the filter.
However, to replace the sand in the filter, you need to first disconnect the pipes going into the valve on top of the filter. Then you need to unscrew the complete valve and once the valve has been removed, you will be able to access the sand bed. The best way to remove the sand is to either use a portable vacuum or just tip the contents into a small container. Then clean and fill the tank 2/3 full of water and just pour in the new sand. Avoid sand entering the vertical pipe that protrudes from the bottom of the filter tank.