Clean and dry the back of your aquarium.Slip the top edge of the background underneath the top trim piece of your aquarium. Make sure there is enough background to allow for water spillage to drip down the outside of the background, rather than between the background and the glass.
PETCO Double Sided Aquarium Background
Dimensions: 19.25"L X 31.5"W
PETCO Double Sided Aquarium Background
Dimensions: 19.25"L X 48"W