On aboveground swimming pools, your filter sand should be changed yearly; inground pools about every 5 years. The reason is that over time, the sand crystals round off and become less effective at filtering the pool water. A buildup of oils in the sand, which do not backwash out, also make the sand less effective at cleaning the water.
It is a good idea, if you are in an area with temperature extremes in the winter and periodic freeze/thaw periods, to remove the sand before the temperature extremes hit. Leaving the sand in the filter during freeze/thaw periods may cause the lateral assembly with center pipe inside the filter to crack.
The easiest time to change the sand is in the spring before opening the pool while the water level in the pool is below the skimmer and return lines. At this time, you do not have to worry about plugging the return and skimmer lines to prevent water from running out of the pool.
To change sand in your pool filter, follow these steps:
- Remove the top valve from the pool filter. This is done by removing the clamp which holds the valve in place.
- Depending on the size of the filter, you can either dump the filter out by tipping it on its side, or you can vacuum the sand out with a shop vacuum.
- Once most of the sand is removed by the shop vacuum, wash out the filter tank.
- Check the internal lateral assembly and center pipe to make sure there are no cracks in it. Make sure that the laterals are screwed in tight to the center pipe.
- If your internal assembly has fold up laterals, make sure they are in a horizontal position. If not, you may experience sand shooting back into the pool when filtering.
- Once you are sure that the center assembly is okay, position the assembly in the middle of the filter tank.
- When adding sand to the filter, you do not want sand to go in the center tube. You can cover this tube with a plastic bag, a sock, or something similar.
- While adding the sand, make sure the center assembly stays in the proper position.
- Fill the filter tank half full of water, and make sure the drain cap is in place and not leaking.
- Add the proper amount of sand. This is usually shown on the filter tank label. If unsure of the proper amount, contact your pool professional with the make and model of the filter. (If you can not locate the make an model, a general rule of thumb is to fill the tank 1/2 to 2/3 full).
- After all of the sand is added, clean the top of the center assembly where the valve attaches. Failure to do so may make the valve impossible to remove as sand will jam between the center assembly and the valve. Also clean around the top of the tank where the valve sits.
- Check the o-ring that is on the valve to make sure it is in good condition otherwise the filter will leak between the valve and the tank. If it is bad, replace it.
- Reattach the clamp to hold the valve in place. At this time, I like to remove the hose connectors and re-tape them with teflon tape to assure they will not leak. Now, reattach the hoses.
- Make sure the pump and strainer drain plugs are in place, and the "O" rings are in good condition. Remove the strainer cover and check the "O" Ring. Lubricate if necessary. If in poor condition, replace. A poor "O" ring at the strainer cover will allow air to get into the filter and give you filter operating problems. Prime the filter pump by adding water to the pump. Startup the filter in the backwash position to remove the dust particles from the sand.
- Check the filter for leaks
Please call us at 677 - 4100 if you have any questions about changing sand in your sand filter.