Larry Lunsford

Salt is a common chemical that can be of great help in your Koi pond. There are two ways to use salt for your Koi: as a salt bath, or directly in your pond. Salt improves your Koi's health by killing parasites. Relatively minor changes in salt level will not affect your Koi, but it will kill parasites. Continual use of salt is not recommended since the parasites will become acclimated to any salt level. It’s the changing salt level that kills the parasites. Salt can also help your Koi deal with other problems. The only draw back to the use of salt is that it is bad for plants. Depending on the variety of plant and strength of salt, the plant may be slightly bothered to killed by salt (this includes your grass and bushes - watch where you dump salt water). For a complete description of the use of salt, see Dr. Eric Johnson's book "Koi Health and Disease".

When treating with salt, use only pure salt. Do not use anything with chemical additives (chemicals are sometimes added to prevent rusting or clumping in water softeners). Pure salt for water softeners can be found at any home improvement store for $5 to $10 for a 50 pound bag.

Salt Bath: A salt bath is a quick treatment using a high dose of salt. A salt bath should have 3.0% salt. This works out to 4 ounces of salt per gallon of water. Prepare a tub with salted water. The tub needs to be big enough to comfortably hold your Koi. Use enough water to completely cover your Koi. Thoroughly dissolve the salt. Thoroughly aerate the salt bath tub while treating your Koi. Have a second tub of fresh water to hold your Koi before and after the salt bath. Make sure the water in the tubs is dechlorinated and close in temperature to your pond. Once everything is ready, put the Koi to be treated into the salt bath. Leave the Koi in the bath for 10 minutes or until it shows signs of stress (particularly rolling over). Small Koi or Koi that have never been treated with salt may show signs of stress quickly. For such Koi, repeat salt treatment daily or every other day until the Koi is able to take several minutes of the salt treatment or for three to five quick treatments.

Salting Your Pond: As a parasite prevention measure, salt can be used in the whole pond. When salting the pond, you want a dose of 0.3% to 0.4%. Apply salt in doses of 0.1%. A 0.1% dose of salt is about one pound of salt per 100 gallons of water (1 pound salt per 100 gallons is 0.12%). Apply the 0.1% doses daily to reach your target level. Mix the dose in a bucket of water and spread it around the pond to avoid killing plants with too strong a dose. After your have reached your target dose, maintain the dose for a couple weeks. Your can remove the salt gradually with routine water changes. Early spring is a good time to salt your pond to keep parasites from getting the upper hand on your Koi.

When treating your pond, it is important to dose accurately. If you are not sure about the volume of your pond, or if you have done water changes or other things that would cause you to be unsure of your salt dose, use a salt test kit to measure your pond's salt content. Aquarium Pharmaceuticals makes a good test kit that is inexpensive.