Abstract: A swimming pool filter including a casing having an opening and a filter cartridge arranged in the casing having an axial hollow core. The swimming pool filter also includes a top cover having means for securing the top cover to the casing in order to cover the opening of the casing and an opening substantially corresponding to the axial hollow core of the filter cartridge. The swimming pool filter further includes a plug structured and arranged to fit within the opening of the top cover and an accessory element arranged in the plug to complement the functions of the filter. The accessory element is structured and arranged to fit at least partially within the axial hollow core of the filter cartridge when the plug is fitted within the opening of the top cover.

Abstract: A swimming pool filter including a cylindrical receptacle made of plastic material and casket-forming ends to which a valve head is coupled, the latter to be connected by conduits to a diffusor and a manifold located, respectively, at the top and bottom of the receptacle; the filter including sand as filtering material, and a buffer is located between the bottom of the receptacle and the manifold occupying a predetermined sand-free space, which buffer when subject to an inner overpressure that causes the receptacle to expand, prevents the sand from accumulating at the bottom of the receptacle, thus neutralizing the pressures that may act upon the manifold. The cylindrical wall of the receptacle is reinforced with a band made of a resistant material.