Dimart Dark Gray High Imitation Water Hide Hollow Tree Log Plant Decoration for Fish Tank Aquarium (Contian of A Gift Blue Yellow Black High Imitation Lionfish Landscaping Ornament) Higfh quality: made from polyresin, it is non-toxic and has no effect on water quality They're are absolutely safe for fish and best of all, they won't die, rot or cause any algae problems. Great Detail in Design in a Tree Root design Offers the natural environment feeling,change your aquarium into a beautiful scenery. It is vividly and colorful detailed to add lively and natural life to your tank.