Pond salt is one of the most versatile and affordable tools in a koi keeper's arsenal. Play It Koi carries pure, non-iodized pond salt in a range of sizes for koi ponds of every volume. Used correctly, pond salt reduces osmotic stress on fish, supports the natural slime coat, inhibits nitrite toxicity, and provides a gentle first-line treatment for many common health issues. Unlike harsh chemicals, salt is natural, does not damage biological filtration at standard doses, and remains in the water until physically removed through water changes.
How Pond Salt Works
Koi constantly expend energy maintaining their internal salt balance against the freshwater environment through a process called osmoregulation. Adding salt to the pond water at a low concentration of 0.1 to 0.3 percent reduces this osmotic workload, freeing energy for growth, healing, and immune function. At higher concentrations of 0.3 to 0.5 percent, salt becomes therapeutic — it can help control certain parasites, reduce the toxicity of elevated nitrite levels, and speed recovery from minor infections and transport stress.
Dosing and Application
Always dissolve pond salt in a bucket of pond water before adding it to the system — never dump dry salt directly into the pond where it could contact fish. A standard maintenance dose is one pound per 100 gallons for a 0.1 percent solution. For therapeutic use, gradually increase to three pounds per 100 gallons over 24 to 48 hours. Use a salt meter or refractometer to verify concentration. Remember that salt does not evaporate — only add replacement salt after water changes, not top-offs.