it is something for putting the pump on the back of the tank
http://ecotechmarine.com/ecosmart/
EcoSmart Nutrient Transport Mode
In this EcoSmart mode, water is circulated in a two phase program consisting of wave motion to stir up detritus and surging motion to move the detritus into your overflow where it can be skimmed out. This effect 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.
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360 gallon sps reef, 180 gal sump, bubble king supermarine 300, 4xmp40Wes, 2 x 6215 tunze waveboxes, 4 ghl mitras
360 Reef Tank