Houyi Aquascaping Terrarium Foam is a high-expansion polyurethane foam designed for aquascaping, terrariums, paludariums, vivariums, and custom aquarium backgrounds. It bonds securely to rock, wood, glass, and other hardscape materials, making it ideal for creating natural-looking landscapes, waterfalls, caves, and structural features. Once fully cured, the foam is waterproof and safe for underwater use in aquariums and aquatic environments. The cured foam can be trimmed, carved, sanded, or coated with substrate, moss, or silicone to achieve a realistic natural finish. Features: Strong adhesion to most surfaces Expands to fill gaps and create custom shapes Waterproof and aquarium-safe once fully cured Easy to carve and shape after curing Suitable for freshwater and terrarium applications Allow foam to cure completely before submerging or introducing livestock. Solidifies within 40 minutes of application. Wait 48hrs for full cure. Colours come in black and dark brown