Oh, okay! That makes sense. I didn't pay attention to the "minimum" part where it said "water level." This is the one I have http://www.petsmart.com/product/inde...ductId=2752191
It is a 50w, and it's so tall that the knob sticks out of the water anyways. I've lost the directions that came with it, but I remember that they had a picture showing that the bottom shouldn't reach to the gravel. Have you had a problem with that? Mine basically has to since it is in a 10 gallon that is divided 3 ways. There's no room to angle it.
Thanks for the pics!