So I am going to be doing my first DWC grow and the main concern for a lot of folks seems to be water temp. I have a 70x48x20 cabinet, 400w HPS/MH, closed ventaliation for the light (75cfm fan intake outside/exhaust outside), and a 75cfm fan intake and 75cfm exhaust for the cabinet. Ambient temp outside the cabinet is 60-68 degrees. Inside the cabinet is 80degrees lights on and 70 off. My idea is to place the air pump outside the cabinet to suck in colder air hopefully lowering the water temp. Anyone ever tried this?