I took a picture of Hannah looking at her fish, I never expected the fish to turn out but they did.

Try putting a very light colored backdrop on the back of the tank, and make sure the room is really bright to and turn of the flash

I think the light was on in the tank but experiment try it with out the light on but make sure the room is really bright.

oh and try it taking the pick sorta like on an angle, not close to the glass and straight on.

Good Luck