Besides the regular backflushing of the sand filter it is necessary after a certain time to change the sand in the filter. In the case of this particular system this is the first time that it has been changed in ten years.
In these photos the sand filter is a 30 inch Lacron model.

This shows the general layout of the sand filter before any work is started. The change over valve can be clearly seen in the bottom of the photo, and below that is the main pump for the system.
At the top of the photo can be seen the twin 30 watt UV unit which is connected to the discharge side of the sand filter. On other pages of the website you will see this has been changed for a 55 watt unit.

This photo shows the tool for the removal of the cover.
The actual tool may vary depending on the type of sand filter you have.

The only way to remove the sand is by hand, and it can be quite difficult and time consuming when you get down to the bottom.
Long arms are an advantage.

When they got down to the bottom around the elements then a wet and dry vacuum cleaner was used, and this was found quite successful in removing the remainder of the sand.

This photo shows the internals of the sand filter after all the sand has been removed, and the body has been washed out.

Everything is now ready for the filling with the new Silica Sand.
The plastic has been placed over the threads of the housing to ensure that none of the dry sand sticks to the threads, and so cause problems when the cover is screwed back into place.
The first bag of Dried Silica Sand is seen ready to be opened and poured into the filter. Eight of these bags were required which adds up to 200Kgs.
When the sand has been added and levelled out, the plastic is carefully removed, and the cover is replaced and tightened up.