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How Much Salt Should I Add to My Pond?

    Pond Salt is a versatile tool in any pond owner’s arsenal.

    This inexpensive, easy-to-find product can help treat a range of fish health  issues – when used correctly.

    Check out our tips below to learn how, when, why and how much to use salt in your 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.

    Pond Salt Calculator

    What Kind of Salt Should I Use in My Pond?

    Make sure that any salt you use in your pond does not contain iodine or anti-caking agents.

    For the most peace of mind, we recommend buying salt sold specifically for pond fish.

    Will Pond Salt Kill My Plants?

    Pond salt will not kill your plants if used at the dosage recommended above. You might, however, see some yellowing around the leaves of some plants. This discoloration is normal and will not cause any issues for the overall health of the plant.

    How Does Pond Salt Work?

    We mainly use pond salt to kill parasites in the pond. Parasitic infections, which are often invisible to the naked eye, are one of the most common causes of fish health issues. This fact is the reason we often recommend salt as the first line of defense when fish seem unhealthy. While salt won’t kill every type of parasite, it does help with many of them.

    Pond salt also has the following secondary benefits:

    • Helping fish combat negative effects of elevated nitrite levels in the water.
    • Restoring fish’s natural electrolytes and supporting natural gill function.
    • Building up fish’s slime coats, helping to prevent disease.

    As we mentioned earlier, we do not recommend using pond salt unless fish are ill. Regular “maintenance doses” can stress koi’s kidneys if used for long periods of time.

    Other Fish Health Tools

    Probiotic Fish Food

    This high-quality food helps keep fish happy and healthy during times of illness or stress. It’s also a great choice for early spring as fish are coming out of torpor.


    Protect helps fish build up a healthy slime coat, letting them fight off pathogens and infections. Protect is a helpful tool for keeping fish happy and healthy in times of stress, including during illness, seasonal changes or water changes.

    Broad Spectrum Disease Treatment

    This treatment uses a mix of malachite green and formalin to help fish fight Ichthyophthirius (Ich), Chilodonella, Costia, Oodinium, Trichodina and fungal infections.

    Pond Detoxifier

    Removes harmful chlorine and chloramines from water you add to your pond. A must-have if you ever do a water change or clean-out – and always recommended to have on-hand in case you accidentally overfill your pond while topping off the water levels.

    Aeration Systems

    Fish can always benefit from extra dissolved oxygen in the water. An aeration system will reduce fish stress, provide backup aeration if the pond pump fails and help keep a hole open in winter ice. 

    Disease-specific Treatments

    If you know exactly what’s wrong with your fish, we carry a wide range of treatments to help fish fight everything from parasites to bacterial infections.