NEW Deltec Vlies Filter The Deltec fleece filter cleans the aquarium and filters the coarse dirt out of the water. Once the fleece is loaded with dirt and saturated, the water in the Deltec fleece filter rises and the float switch starts the gear motor, which continues to turn the fleece roller. As soon as the roll is used up, the geared motor lifts the deflection roll out of the magnetic holder. This allows the water to drain off and the motor stops. Now the roller can simply be exchanged and the water filtration can be continued. The emergency overflow also ensures that the water is returned in a controlled manner if the water level in the filter should rise.