take a piece of plexiglass 1/8 or 3/16 th , measure the back of your tank includeing the trim. velcro the trim of the back of the tank- paint the plexiglass with FUSSION SPRAY PAINT its made by krylon design for plactic( make sure you you dust the paint on not heavy coats, light coats.
It comes out great **
good luck
donald
new fish