Normally, these filters have a 6-position valve where one of these (backwash) is used to wash sand inside itself by draining water.
This process has to be carried out every 7-10 approx. Sand filters use different types of sand, normally quartzite, which may have different grain sizes depending on the use and on the kind of filter.
According to our experience of the last years, we now use a kind of sand of volcanic origin, ZELBRITE, which has a filtering power of 1 micron and also absorbs ammonia while eliminating the use of the flocculants.
These filters are normally used for small-and medium sized pools or where the draining of water is not possible. This could be due to technical reasons, the lack of a dedicated drain, or to the limitations imposed by some municipalities as far as water draining is concerned. Cartridge filtering has a good level of filtration, some microns depending on the producer; has very small dimensions but needs a frequent service (every 2-7 days depending on the dimensions). Above all, it must be physically removed from the filter and washed thoroughly with a water jet, being careful that every "polluting" body must be removed.
Chemical treatment of pool water
As far as the chemical treatment of pool water is concerned, the most used products are CHLORINE, FLOCCULANT, ANTI-SEAWEED, PH CHECKER.
PIn order to keep the values within the set parameters, there is also the possibility to schedule automatic or manual analysis and dosing.
In fact, there are units that analyze the values of the pool water and dose the needed quantity of product accordingly.
This analysis, in addition to the manual supplement of products, is used in small-and medium sized pools.
An alternative to CHLORINE is ACTIVE OXYGEN, which we have been using for many years now with excellent results.
AVTIVE OXYGEN is a dry product which has not to be confused with liquid Oxygen or Peroxide.
It has high disinfectant properties, almost equal to those of Chlorine, however without the same unpleasant effects like odor and eye burning.
It is recommended for private pools which are frequented mainly by children or persons with sensitive skin.
The use of ACTIVE OXYGEN allows also to reduce the use of pH checker since Oxygen already has a very low pH.