Water filtration and circulation systems are decisive for the correct use of the pool. The water recycling system recycles water from the pool and conveys it for filtering, disinfecting and then back to the pool.
The filtration is the elimination process of floating residues.
The key components to guarantee the correct filtration are: filter body, pumps, pipes and valves and control panel. The times and speed to guarantee a good filtration are adjusted according to local regulations. There are traditional media filters (like sand) or new generation ones.
in the last years new systems have been developed to resolve the disadvantages presented by the sand system. One of the solutions developed is pearlite: it guarantees an excellent filtration quality (1/2 micron) and minimum quantity of energy and water is used; in addition diatom is substituted by pearlite, it is completely automatic and it occupies little space in the technical room. On the other hand the initial investment is more expensive since it is not frequently used.
the sand filtration systems are simple to use, very acknowledged and have a low maintenance schedule. However they do present some disadvantages: the counter current wash requires high quantity of water, they have an average filtration quality (20/30 micron) and relevant spaces are needed for bulky filters.
there are many other alternative systems that have been developed: filtration systems with cartridges for small pools and exceptional cases; systems with glass filter media or zeolite instead of sand to increase the filtration quality; and the so-called Ultrafiltration still at experiment level.