The microbubbles created in the system trap impurities as they rise and create a scum at the top of the column. This scum which is sucked up by the vacuum carries with it the particles which are trapped inside. These extracted particles are between 0.3 and 30 µm and are not trapped in conventional systems.

Particle extraction by the COLDEP system also makes it possible to trap bacteria and viruses, thus ensuring the biosecurity of breeding waters. Water clarification also helps to ensure optimal UV efficiency, coupled with the extraction function which eliminates degraded particles that UV and ozone treatments neutralize but leave in the environment. There is the possibility of extracting continuously or only a few hours a day.