I hate when my pastel UR's just as I am going to bed. It is always a flood and he looks so helpless sitting on top of his hide.
He always does it right where I have the accurite attached.

I use 8oz deli cups for water and I took an empty cup and used industrial velco on the floor of the cage and back of the cup to attach it to the floor of the tub then I just pop in another cup w/ water. Never a spill and the industrial velcro (sp) I use is made for outdoors so all the cleaning in the world has yet to loosen it up and it's been over a year now. Easy pop in pop out the second cup to change water.
I do the same w/ my accurite temp gauges. Little pc of velcro on the front top of the gauge and the other along the side of the tub. Then my accurite is right along the front of the tub where I can check temps and not have to open the tub.