EcoSmart Nutrient Transport Mode
In this EcoSmart mode, water is circulated in two phases – a wave motion to stir up detritus, and a surging motion to move the detritus into your overflow where it can be skimmed out. This mode promotes maximum health and nutrient export, as well as increased growth for sensitive corals such as SPS.
Adjusting the dial changes the maximum speed achieved at any time during this mode. Slave pumps should be positioned opposite the master and on the back of the tank to take full advantage of the EcoSmart modes. Short pulse is added to this random flow. So now through the day I get 5-6 random flow... If you go to ecotech website it'll give you more detail.