Introduction Miami Science Museum, located in Downtown Miami in Bicentennial Park, is a 180,000 sq ft facility that includes a planetarium, 500,000 gallon natural seawater tank, wildlife exhibits and venue spaces. The elliptical pool, 100 feet in diameter and housing exotic fish, features a large underwater viewing window. In addition, waterproofing and corrosion protection was needed for the perimeter walls, slabs and pools in other areas of the site. Challenge The tank’s elliptical shape and viewing window made finding a durable waterproofing solution both challenging and critical. Also, it was important that the tank’s constituent materials and construction not impact the wildlife species housed in the tank. Finally, because the tank contains seawater, protecting the steel reinforcement from corrosion was an important design consideration. Solution The project consultant recommended the use of Hycrete System W, Hycrete’s integral waterproofing system, to provide protection in the concrete backed by the company’s performance warranty. Hycrete’s integral admixture also provides corrosion protection throughout the concrete mix by both reducing absorption and protecting the surface of the steel reinforcement. Hycrete W1000 is Cradle to Cradle CertifiedCM Gold and NSF/ ANSI-61 certified (approved for use in potable water tanks), an important consideration for the sensitive wildlife contained in the tanks. Result In addition to waterproofing the seawater tank, Hycrete was used in perimeter walls, slabs, and pools in other areas of the site. The tanks and pools are leak-free, and the concrete mix produced excellent results, meeting all of the important performance parameters required by the specifications. The owner has a long-term solution throughout the concrete mix that is environmentally-friendly and compatible with the sensitive needs of the fish species living in the pools and tank.