Even a small swimming pool filter requires upwards of 60kg of sand in addition to the liquid. To cope alone with such a weight is no easy feat.
How to change pool filter sand
First of all, you need to drain the water from the filter, after closing the valves from the pump and from the jet line.
In filters with a “top head”, turn off all the nozzles, remove the collar, and take out the 6-position valve. This provides you with access to the sand so that you can change the sand in the pool filter.
In filters with a side valve, simply unscrew the top cap and remove the sand from the pool filter. It is often not necessary to loosen the connections.
In low filters that do not have hatches for unloading the sand, the removal of sand can be performed the old-fashioned way – with a scoop or by using your hands. In the latter case you will need flexible hands, since the gap between the supply pipe and the neck of the filter is very narrow. When extracting the sand, you really need to wear long sleeves, otherwise all your arms will become scratched. Make sure you don’t unscrew the trace separator together with the tube for draining the water from the bottom of the filter. If you do this, sand will pour out along with the water and will clog all the drain traps.
After removing the sand
– check the integrity of the separators, so they are not damaged when they are unloaded;
– in the filters with a “top head”, the separator pipe should be exactly in the center;
– place a plastic bag of sufficient strength over the separator pipe. If the filter is large, and the cowl is too big, it’s a good idea to put foil over any sizeable objects. Usually when installing this equipment, an angle is used for the fitting that would prevent sand from falling into the pipe and that would support it in such a way that sand would not cause the socket to close. Now the package will not break.
– pay special attention to the tube of the air-trap. When unloading, it can easily be pulled away from its fasteners, bent or damaged. As a consequence, sand can end up in the pool basin, and you will be left with the subsequent cleaning and troubleshooting.
During the backfilling of sand, the package marking the edge of the bag at the neck of the filter can become cut. In this bag the weight will fall on the bell of the pipe and will move it.
It is customary to open the bag, by just cutting the corner of it. In this case, it is necessary to consider that some bags of domestic producers will have a thin inner plastic bag that protects the sand from getting wet and dirty. Cut off the corner of the bag from the side opposite the seam. The seam is also stitched to a protective package and holds it in place, while its other side will try to fall out, together with the sand inside the filter. If this is missed, you will have to produce a “device” for removing pieces of cellophane out of the sand.
According to the rules, before the backfilling of sand, the filter should be 1/3 filled with water to protect the separators from falling sand.
If you take care to fill it with gravel or sand until the separators are hidden, it is possible to manage and without this step. After filling half of the sand, water starts pouring in from the top, and you need to create a pit in the drain valve.
Assemble the filter in reverse order and then open the right valves.