In every pool or tub, good filtration equipment is of the utmost importance since it is a key factor for hygiene and water maintenance. The main function of these devices is to release water from the solid impurities suspended in it in order to prevent our body from absorbing them through the skin. For this reason, it is essential to carry out a deep cleaning process that allows us to reduce to the maximum the dirt and harmful elements present in our appliance. It should be noted that although the water looks transparent and clear, it can have invisible particles as polluting as those we can see easily. That is why it is necessary to execute a disinfection technique with chemicals in parallel or after filtering. Water filtration represents almost 80% of the effectiveness of its maintenance, so, knowing what is the best mechanism is the first step we must follow. Its system is composed, primarily, by the pump for pools or tubs and the filter as such, both elements play a crucial role in the water purification process meanwhile the former allows its circulation and the latter purifies it. In the market, there are several types of filters but the most convenient in every case will depend on the requirements of each person, its operation is quite similar although each one has its advantages and disadvantages individually. All of them demand, mainly, the pumping system that allows the movement of the water so that it runs through the purification circuit. Then, it passes to the filter to be freed from all the unwanted particles and it is returned to the container. The most common filters are sand filters, cartridge filters and diatomaceous earth filters. Sand filters are composed of a compartment containing silica sand, which is responsible for filtering the water, removing organic waste such as dirt, hair or body oils. This type of devices is the most demanded as it does not require a lot of maintenance and it can last even more than 7 years without needing to be replaced. In addition, the procedure that they carry out is natural and chemical free. On the other hand, we have cartridge filters; these systems are based on cleaning through replaceable cartridges that have the ability to separate very tiny particles from water. This method requires more maintenance considering that cartridges have an estimated life time that ranges between 6 and 12 months, moreover, they must be cleaned weekly to make them more effective. Finally, we have diatom or diatomaceous earth filters, their operation is very similar to that of cartridges, however, they have diatom or diatomaceous earth; small fossilized elements whose main property is to filter the water. Its power is superior to that of other methods since it manages to absorb even those particles so small that they are invisible to the human eye, they are also capable of eliminating the remains of oils and tanning creams. They are very advisable although they are the most expensive option among all. To be able to choose which the best type of filter is, it is important that you analyze the characteristics of your tub or pool and, in this way; you will know which is the most suitable for you.