After we moved from the first apartment I had a SW tank in, we started putting down plastic floor mats... you know the "Hi traffic" area stuff you can buy at the Hardware store. Works wonders, as I spill quite frequently. It's also a good idea to put a carpet runner or something in front of the tank, as you undoubtedly will drip pulling things in and out of the tank.
If I had the time, money, and space, I would get the floor underneath tiled and a floor drain installed, but... Those three precursors are in short supply.
- Mac