Nature's Image Corals are exact replicas of natural corals that occur on coral reefs around the world. Made of special high-grade materials, they are completely safe for the livestock and water quality in both fresh and saltwater aquariums. These coral replicas can be placed in the aquarium immediately, there is no curing time. Of course, a freshwater rinse is always advisable to remove any packing residue or dust. These coral replicas are not painted or dyed; the color of the piece is solid throughout. These coral replicas are UV color stabilized, which can guarantee 95% color retention over years of exposure to both aquarium lights and sun. The natural build up of algae can be considered by some to enhance the beauty of an aquarium. However, if cleaning is required, a gentle scrubbing with a soft toothbrush works well. If you prefer, you may soak the piece in a 50% - 50% bleach and water solution. * Made of special high-grade materials. * Completely safe in fresh and saltwater aquariums. * Can be placed in the aquarium immediately, without curing time. But a freshwater rinse is always advisable. * Not painted or dyed the color of the piece is solid throughout. * UV color stabilized - 95% color retention is guaranteed over years of exposure to aquarium lights or sun. * To remove algae, a gentle scrubbing with a soft toothbrush works well. If you prefer, you may soak the piece in a 20% - 80% bleach and water solution.* CAUTION: When using bleach allow it to dry and set, at least 24 hours in the sun, in order for the chlorine to dissipate.