Functioning of the sand filter

A handle on the filter casing controls the multi-way valve, directing the water stream in such the way so that it flows through the filter. The handle can be set in any of the three positions. (Concerning the sand filter originating from P.H.U. ANITA IMPORT-EXPORT; Swim-Tec)

Normal filter setting. The water from the swimming pool is pumped downwards through the filter and back to the swimming pool.

This setting is used for washing the filter when it is very dirty. Water from the swimming pool is pumped through the filter in the opposite direction. The sand layer is stirred and pollutions are separated and through the upper separator flushed to sewage system. During the backwash, water is consumed. Sand stays in the tank.

The setting is used for washing away the dirt from pipes after the backwash procedure. Water flows in the same direction as in setting 1, the only difference being that water goes to the sewage system and not to the swimming pool. Sand settles at the bottom of the filter again.

It enables circulation of water bypassing the filter. This setting is used in case of filter breakdown.

Water is pumped from the swimming pool directly to sewage system. The setting is used for lowering the water level or if we do not want to overload the filter during vacuuming large pollutions from the bottom of the swimming pool.

This position is used with the pump switched on only. It enables opening the pump cover and cleaning the strainer, obviously under the condition that the valve between the pump and the swimming pool is closed.

Attention! Always switch off the pump when switching the filter valve.


The filter gets clogged with pollutants. The pressure between the pump and the filter increases. The pressure is read out on the manometer and in case it is higher than 0.25 bar from the filter measured on a clean filter, backwashing should be performed. Usually, backwashing performed once a week or in case of increase in pressure by more than 0.2 bar (20 kPa or 3 psi).

Backwashing is performed in the following way:
– If you have electric heating, switch it off
– Switch off the pump
– Close the valves on the conduits leading to the swimming pool
– Open the pump cover, empty the strainer and close the cover again.
– Open the draining valve
– Set the handle to “BACKWASH” position.
– Open the valves on the conduits leading to the swimming pool.
– Switch on the pump and let it work for 1 – 2 minutes. If the filter is fitted with an inspection glass, you can switch the pump on when the water in the inspection glass is clear.
– Switch the pump off again.
– Set the handle to “RINSE” position. Switch the pump on for 30 seconds.
– Switch off the pump and set the handle at “FILTER” position.
– Close the drainage valves.
– Start the pump and electric heating if needed. Read out the manometer readings.


Dear customers,

We would like to inform you that despite the current difficult situation related to the COVID-19 virus, we have taken all necessary measures to maintain the smoothness of our service and delivery times for our customers.

Unfortunately, the increasing number of border controls throughout Europe, as well as the closing of borders with neighboring countries, also affects the areas of our operations and services. We expect delays in procurement and deliveries, so at the moment we are unable to guarantee exact delivery dates.

We kindly ask you to be patient in case the goods do not arrive on time. The current situation presents us with many challenges and we are doing everything we can to adapt to these difficult conditions.