How Much Salt Should I Add to My Pond?

When to Use Pond Salt

We only use salt in our ponds at Splash when fish are ill or experiencing issues with parasites.

We do NOT recommend regular low-level salt treatments for maintenance. Salt is toxic to koi if used at high levels OR for long periods of time, causing kidney damage.

Only use salt when necessary – and always consult a professional if you’re unsure of the best treatment for your fish.

How Much Pond Salt to Use

When calculating how much salt to add to the pond, being precise is crucial. Salt is toxic to koi if used at high levels (water salinity above 0.5 percent).
Use a tape measure to calculate the exact size of the pond – in gallons – before proceeding.
Length (ft.) x Width (ft.) x Average Depth (ft.) x 7.48 = Approximate Gallons of Water in the Pond
Adding 1 pound of salt per 100 gallons of water will bring the salt levels up to 0.1 percent. To kill parasites, you’ll need to slowly bring up that level to 0.3 percent over the course of three days. 
For a 1,000 gallon pond, then, you would need to add 10 pounds of pond salt per day for three days to effectively treat parasites while keeping salinity at a safe level for fish.
For the most peace of mind, we recommend using a salinity meter (coming soon to Splash) to ensure accuracy.