AstralPool ¾"" collector arms or crepinas for sand pool filters.
The function of the crepinas is to capture the water from the bottom of the filter once it has been filtered. When the filter is being washed, they are responsible for lifting the filter load and evacuating the waste retained in the filter.
From time to time (8-10 years) it is advisable to completely empty the filtering load of your pool filter and check the existing crepins in the filter.