Ok, i need to build a tank stand for my 55g and i was thinking of making it a double stand to save on floor space. My question is how do you service the bottom tank, i.e. (pouring water into from a bucket,service filter)? I currently have a 15 gal but i may get rid of another tank to get a 33L which has the same footprint as a 55G. Thanks in advance Zach