Saim Glowing Effect Artificial Coral Plant for Fish Tank Decor Aquarium Ornament Glowing effect requires black or blue lighting for the fluorescent glow highlight, do not mean "GLOW IN THE DARK" Made of non-toxic plastic silicone material , harmless to all fish, both for fresh or saltwater Ideal decoration for any aquarium or fish tank, easy for daily washing Total size : 8.5cm/3.3" base width, 9.5cm/3.7" Inch height. NOTICE: In order to get better fluorescent glow high, PLS put Blue, Pink, Purple coral under aquarium PURPLE RED or RED lighting; and the GREEN, ORANGE, YELLOW under BLUE or BLACK light. Thanks