You might want to do some research on the "berlin method" or "Jaubert method" and strip down one of your smaller tanks to test out how it works for you.
As a note to anyone else looking to set up a reef tank, I suggest you do some reading/research on those two methods. Your main expense will be the lighting and liverock. A lot of the equipment for either method you can build yourself. So price wise, it does not need to get ridiculous (well no more so than a comparably-sized fresh water tank).
I'll post some photos of the results of these methods.