Pond salt is something every fish or koi owner should have on hand at all times. Adding pond salt will help boost your koi’s natural defences to disease and add beneficial electrolytes to the water.
Non-iodized salt, Sodium Chloride (NaCl) is commonly used in the health care and maintenance of fishes, especially Koi and goldfish. It is inexpensive, safe to use, it will not harm your biological filter, it is useful in treating parasites and helps fight the effects of nitrite toxicity. Make sure that the salt contains no YPS (Yellow Prussiate of Soda) in it because it is hazardous to fish.
It is recommend that you use salt, before you try anything else for parasites because it has so many benefits over other medications.
Most fish have an internal salt concentration of 1.0% or 10 parts-per-thousand (ppt) which is higher than their water environment. Osmosis causes water to transfer from the lower salinity of the pond water into the tissues of the fish. Addition of salt will lower the osmosis pressure. This reduces the effort of the fish in eliminating the excess water. The saved energy is then available for use by the fish’s own immune system to fight diseases.
Salt concentrations between 0.3% and 0.5%(3 to 5ppt) will upset the osmotic balance of some parasites i.e. the parasites’ cells will dehydrate. Salt concentration of 0.3% are effective at detoxifying nitrite and concentration of 0.25% or higher has been used to control some string algae species. Nevertheless, salt can cause pond plant damage as the concentration increases. Floating plants (water hyacinth, water lettuce, etc.) are affected at lower concentrations than most bog plants.
Adding salt in the pond especially in the fall will help fish survive the long cold winter months. We recommend adding 1 – 3 lbs of salt for every 100 gallons of water in the pond. We often add salt in the fall, after taking out floating plants such as water hyacinths and water lettuce.
We carry the KoiMedic Salinity Tester and the Economy Salinity Tester. These pond salinity meters are specially designed to measure the salt concentration in ponds. These meters are accurate and easy to use. All you need to do is turn it on and dip into the pond water.