Dymax Marine Composeal Bonding Sponge is a non toxic; quick bonding compound that provides long lasting durable and waterproof bonding effect when Dymax Flora glue is added. This bonding compound is fully environmentally friendly and can be easily prepared for bonding reef rocks and artificial coral commonly used for Live Rock Aquascaping. Purple Reef colour matches synthetic reef rock, no cosmetic touch up required.  Used for filling gaps. Strong and durable. Provides a natural look. DM870 50G. Requires scaping glue to bond, Dymax Flora Glue sold separately.