The deionization filter makes it possible to produce a water of very high purity; this step makes it possible to remove the Anions and Cations still present in the water after passing the membrane. Very effective, it will allow you to obtain a rate of TDS close to 0 and a possible conductivity of 0.1?m. Ideal values for reef aquarium!
Do not use where the water is microbiologically unsafe or an unknown quality. It is essential that operation, maintenance and filter replacement requirements be carried out as scheduled so that the system can perform to its optimum ability.