From everything I've read, the ideal depth is around 9" which is where I have mine at the moment and it seems to run well but i think i read somewhere it can be anywhere from 7-10" as long as the depth is stable (doesn't change with evaporation)
The way I have it set up the dimensions are (including all sticky outie pieces
) 16 1/2" by 12".
If it is set up the other way I think it would be approx 11" by 19" ... all these measurements are approx because it is hard to get a true measure with the base underwater but I rounded all the numbers up so it shouldn't be bigger then what i said