Fill the sand filter

Sand filter systems are so popular for two main reasons. They filter very efficiently and require only minimal maintenance. But low means that it can not be done without maintenance. Although the filter medium must be cleaned regularly, the sand must always be replaced. Following you will receive a detailed guide to filling the sand filter.

The maintenance of a sand filter

If you have already compared sand filters and cartridge filters, you should have noticed the significantly lower maintenance costs. While you need to replace a cartridge filter regularly, you only need to clean the sand filter. For this purpose, the system is backwashed and the multi-way valve switched.

Construction of sand filter system and sand filter

To better understand, here first the structure of a sand filter system:

  • Inflow and outflow from the pool (pool, pond, aquarium)
  • Multi-way valve (6-way valve or 4-way valve)
  • Pump (circulating pump)
  • filter housing

The structure of the filter housing:

  • Filter housing, divisible
  • in the "lid" pressure gauge
  • top (inside) water distributor (funnel-shaped, with supply line to multiway valve)
  • sand
  • in the sand below (inside) filter star or filter cross (with supply line to the multiway valve)

How does the sand filter work?

Circulate (Filter)

The water is pumped out of the water basin via the multi-way valve into the water distributor. Now it seeps through the sand and then into the pins of the filter star. The returnable valve returns to the water basin.

Backwashing and rinsing

When backwashing the water is pressed from below into the filter star and discharged above. From the multi-way valve, it is now in the wastewater connection. After backwashing, it goes to rinse (again the same pumping direction as when filtering, but still drain to wastewater). This ensures that no sand and dirt particles remain in the system (pipes, valve).

Renew sand in the sand filter

Remove sand from the sand filter

This backwashing is sufficient for several years. After a maximum of four to five years (depending on the degree of soiling and the general condition of the sand), however, the filter medium itself, ie the sand, must be renewed.

For this purpose, the drain plug is first opened when the system is switched off so that the water in the filter housing can run out. Now the sand is taken. Care should be taken here because it often causes damage to the piping, the water distributor or the filter star.

Refill sand filter

For refilling, it is first necessary that you pick the right sand. Two different grits are used for sand filters:

  • 0.4 to 0.8 mm
  • 0.7 to 1.2 mm

Depending on the system both grain sizes can be used (multilayer filter). A mark for the sand is usually not necessary, as this should be below the housing separation. So with the filter open slightly below the top edge.

Procedure for filling

Until then, fill in the sand. However, be careful not to damage the filter star and vent hose. So that the sand settles better, you should also fill in water. When you have finished filling the sand into the filter, you can close the housing again. However, scrupulously clean the sealing edge of any sand crumbs. If necessary, you can grease the seal slightly.

Prepare the newly filled sand filter to start up

Now you can not immediately put the sand filter system into operation after filling with sand. First you have to backwash the system. A corresponding manual for backwashing the sand filter system is available here.

Tips & Tricks

Some pool owners empty the sand in the sand filter every year to make it winter proof. The sand could remain in the filter for several years and would not have to be refilled annually. To do this, drain the water from the filter housing in time for the first frost (drain plug). Leave the filter open at the top to allow the sand to dry in time for the first frost. You can also winterize the filter frost-free with the sand from the previous year. Some owners of a sand filter system also replace the sand with AFM (activated filter medium or filter glass). This is recycled glass that is specially treated and available in appropriate grades. The service life of the AFM should be significantly higher than that of conventional sand.

Video Board: How To Change The Sand In Your Sand Filter