Maintaining the pool water in optimal conditions for bathing is essential, so in addition to making a continuous control of the pH of the pool water, proper filtration of the pool is necessary. One of the most common filtration systems in most pools, including removable ones, is the sand filter or sand filter.
The sand filter meets the filtration needs of most removable pools. This filter retains dirt from the pool water in the sand located inside the tank. The sand filters for swimming pools Gre, also called sand filtration monoblocks, are compact and very simple to use and maintain. They incorporate all the necessary elements: a pump, a filter, a selector valve and a manometer.
Being able to enjoy the pool at any time involves some maintenance work. With the passage of time, the sand loses its filtration capacity and you must change the sand to maintain the quality in the filtering process of the pool water.
In general, the sand of the pool filter should be changed every three or four years, although it varies depending on the use made of the filter and the chemical products used to treat the pool water. The environment, trees, pollen, insects and frequency of bathing are, among others, the main factors that also determine the dirtiness of the pool water.
To change the sand of pool filters you must have two concepts in mind:
- Type and volume of water in the pool: removable pools of less than 32 m³, elevated pools of 64 m³, and so on.
- Type of filter: the choice of the filter will depend on the pool model.
Knowing the characteristics of the pool and the water treatment plant, you will know the specific load of sand needed by the pool filter. Each filter allows a different load, which in turn depends on the volume of water in the pool.
For Gre pools, each filter can accommodate a different sand load; 20 kg if you have a small pool, or up to 130 kg for large pools.
Steps to change the sand in a pool filter:
- Close the water way to the filter
You should disconnect the purifier, the pump and close all the valves of the pool. The selector valve must be in the “closed” position.
- Empty the water From the filter
You should remove the water that may remain in the filter. In general, the filter has a drain plug at the base, remove the plug or thread to eliminate the water. If the filter does not have an outlet orifice, the water can be removed with the “emptying” function of the selector valve.
- Remove the top cover of the filter
Remove the top cover of the filter, through which you access the interior of the filter tank where the sand is. In most cases, as is the case with the sand filters from Gre, the selector valve is the filter cover itself.
- Cover the collector (Figure 4)
It is necessary to protect the collector of the tank by covering it with a glove, a plastic bag, a sponge or a piece of cloth … to make sure that no sand enters the tube. This collector is located in the centre of the tank of the swimming pool purifier.
- Remove the sand from the filter tank
You should proceed to remove the sand inside the filter. To remove all the sand you can use a professional vacuum cleaner or help us with a scoop, a mini shovel or any other element that will facilitate the task.
- Clean the filter
Once the filter is empty, proceed to clean the tank with a hose to remove remains of sand embedded in the walls.
- Fill up the filter
With the empty and clean filter, you can fill the sand tank again. It is necessary to know the load of sand that the purifier for swimming pools should carry. The height of the sand must not exceed 2/3 of the height of the tank (Fig.4). Flint sand has an unlimited duration and should only be replaced in case of loss. The sand of the pool filters must be uniform inside the sealed tank.
- Uncover the collector (Figure 4)
You must also make sure to clean the upper slots of the filter and close it back. This aspect is very important since the sand could render the lid unusable.
- Close the filter cover
Once you have cleaned the joints of the lid, close the filter with the top cover again.
- Washing and rinsing
Once again you open the pool stopcocks and before starting the filter again, you perform two functions of the selector valve. For this you must change to “auto clean” for approximately two minutes by placing the hose at the outlet of the drain (waste) and the other end in a sewer or drain. Finally, you must change again the valve to the “rinse” option (for valves with more than five functions) and you will connect the pump for one minute and then switch back to the “filtration” option.
You repeat this process until the water comes out clean. Performing a wash and rinse periodically is essential to maintain the sand of swimming pools filters in the best filtration conditions.
Finally, you put the valve back in “filtration” mode and you have the pool ready for a long season of dips!
For more information about Gre’s removable pools and filters or products related to swimming pools, you can subscribe to Gre’s blog and follow us on social networks.