- 3D Aquarium Background – Beige Rock – to fit 4 by 2 foot tank. The exact 3D background size is 117x56cm cut into 2 halves. On the back of the background, there is a connecting system which helps to position and joins both sections together at the same level. Brand : Aqua Maniac Symbol : 4 foot by 2 Background Sections: 2 sections Background size: 117x56cm Colour: beige Thickness of background : 1-2.5 inch Aquarium Model : 4 foot by 2 foot Aquarium type : Discus, Tropical