If you're running out of space or your snake tends to knock stuff over, you can also put water and sponges in a tupperware container with the lid closed and then poke a whole bunch of holes in it. Depending on where you make the holes, you can then hang it on the side of the cage instead of having to be on the bottom. That will let the water evaporate out over a longer period of time so you won't have to keep soaking stuff every few hours.