This may seem like a ridiculous question, but does anyone have any tips on unsticking a suction cup? I have a 2 1/2 gal. tank that is home to a guppy. In it I use a Whisper micro filter. The problem is, I took out the filter to change the gravel (it had that nasty painted gravel in it) and one of the suction cups stayed stuck to the glass. I can't reattach it to the filter without taking it off, and currently some water shoots out the back where the s.c. is supposed to be. I have tried everything I can think of but it is stuck good!