Penn-Plax Glow Play Pair GLOW PLANTS BY PENN PLAX: the plant will provide a cool look to your tank with its glow-in-the-dark feature, and will stay where you put it because of its weighted bottom. SAFE FOR YOUR TANK: this plant wont harm your fish or live plants, because it wont release anything harmful into your water. DIMENSIONS OF THIS GLOW PLANT: this glow plant is 8.5 inches tall SHOP PENN PLAX FOR ALL YOUR AQUARIUM NEEDS: for a custom look, combine with other Penn Plax aquarium decorations and ornaments (sold separately).