Herco H-55 Pond Coating - One Quart - Black Easy-to-apply environmentally-friendly coating for concrete, brick or block ponds. Eliminates the problems associated with new pond construction. 100% Fish-Safe product with high elongation, excellent adhesion, and durability. Fast curing and easy to apply with a roller or brush. Herco H-55 seals off concrete pores, providing an inert environment for your fish and promoting healthy algae growth. Herco coating is economical to use and long lasting. One gallon of Herco H-55 Coating covers approximately 20 to 25 square feet. Instant pH stabilization. Easy to apply with brush or roller. Quart size can. Professional results every time!