Andy, I have a set up at work and at home just as you described. My basement at work is also cold and I do not have a cover on the sump/refugium. I have (5) 300 watt heaters in the sump. Keeps the temp
a constant 78.
Set up at work is a 175 bow DT. It is supported by a 3'x5' sump/refugium in the basement. I use a MAG 36 with a couple ball values and 'T's' that allows me to control how much water flows back to the DT and how much gets recirculated back into the refugium part of the sump. The system is 'Hard wired'....all PVC. One inch from pump to DT, 2" return from DT. I think a system like this is great because you can do all your water changes in the basement and not have to worry about spills on a carpeted/hardwood first floor. I have an RO/DI unit adjacent to the basement sump so I can keep all the 'back room' stuff out of sight.
Oh...The run from the tank to sump is about 15 feet. (3) 90 degree T's and
a total vertical rise of 6 feet.