Jungle Fortified Pond Salts Fast-dissolving pure crystals with minerals, trace elements, and allantoin (a natural protectant that promotes wound healing, tissue repair, and cell regeneration). Adds and replenishes essential electrolytes and minerals utilized by fish and plants.Safe to use in ornamental fish ponds and water gardens. Safe for freshwater aquariums and plants.Stimulates the fish’s slime coat, which acts as a natural protective defense against bacteria and parasites. Also reduces elevated nitrite levels (toxic to koi and goldfish).2 lb. (907 g) Jar Jungle Pond Clear-Zyme(reg) Bio-active cleaning blocks keep pond water clean and clear. Each contains billions of beneficial bacteria and enzymes that quickly break down the unsightly wastes that accumulate on the bottom of ponds as a sludge layer. Also ideal to use when setting up a new pond and during the spring start-up and fall shut-down of established ponds.Save for ornamental pond fish and plants.To start and maintain ponds, use one block for each 250 gallons (950 L) of pond water once a month.Four 1 oz. (28 g) blocks per package.