i dunno why you couldnt. as long as the water can get in and out of the wavebox it should work. it just needs one hole big enough for the stream to poke thru, and the top needs to be open - not airtight. tuning it wasnt a breeze but far from impossible, that diy controller has a trim pot for coarse adj and another for fine. once its set for the tank, you never have to adjust it. i agree about disliking the box inside the tank...its not that its ugly, its just big and bulky. the fish love the wave action though. it faithfully reproduces a wave and the fish bob and swerve in the current. i havent seen anything that comes close to the tunze, save for the video of the two vortechs making what looks like a 10 inch wave without a box.
edit: wow nyvp i didnt see that you had a 2000 gallon tank! i dunno if it will work in a tank that big? theoretically it should as all it does is get the water moving at the resonant frequency of the tank. maybe just take a bit longer to get the surge going in your tank vs a smaller one.