Goldfish and Aquarium Board Articles
Treating Ich with Salt
By Mango Fish

Ich (Ichthyophthirius multifilis), commonly known as white spot disease, is a protozoan parasite with a complex lifecycle. Ich can be seen as is white cysts that look like grains of salt sprinkled on the fish's body and fins. These cysts (trophonts) drop off the fish and release 200 to 1000 tomites (the free swimming stage of ich) into the water. The free swimming tomites, invisible to the naked eye, will then seek a live host. When tomites attach to a host, they mature into trophozoites and bury themselves into and under the skin of the fish and become trophonts (white cysts) and the cycle starts again. Understanding the life cycle of ich is beneficial because it is only during the free swimming stage that you can kill this parasite, so even if the spots are gone you will still have treat for several days to make sure that all the swimmers are gone. Also, we can reduce the amount of ich present by vacuuming the bottom of the tank/gravel bed since this should remove many of the mature trophonts just released from the host. The ich life cycle will be faster at higher temperatures so to speed up the development of the trophonts it is recommended to keep the temperature in the upper 70s.

Symptoms: Infested fish display the typical signs of irritation (clamped fins, fin twitching, and flashing--swimming quickly against objects in the tank) and may look like they have been sprinkled with salt. In the early stages of infestation, you might only see a few trophonts (white spots). Be sure that what you're seeing is ich because male goldfish get breeding stars on their gill covers and on the leading ray of their pectoral fins which may be mistaken for ich. If the fish is heavily infested, it is likely to sit on the bottom of the tank and wait for the end to come. With Koi you may need to scrape and scope the fish to properly identify the parasite because they are less likely to show the spots characteristic of ich. Ich can be avoided with a proper quarantine protocol.

Here is a picture (by Corrine Wagner) of a comet with ich. Note the white grains of the ich cysts all over the body and on the fins. You can see that the fish is irritated as it is clamping all its fins.

Here are some other pictures of what Ick looks like:

Treatment: Salt (sodium chloride or NaCl) is a much gentler medication than Ich medications commonly sold in pet stores. Some commercial parasite medications can push a sick fish over the edge. Salt will not harm your filter bacteria, it’s cheap and will not harm humans coming into contact with it; however, not all fish tolerate salt. We recommend it only for cold water fish like Goldfish and Koi. Tropical fish are best treated with a malachite/formalin combination like Rid Ich or Quick Cure. Salt may also kill some plants, so you will need to remove any live plants into another container and disinfect them (Potassium Permanginate works well for disinfecting plants). The salt must be fully dissolved in tank water before adding it to the tank. Most any salt will work fine. Rock salt or pickling salt work great and are cheap. Avoid using salt that contains yellow prussiate of soda

It is very easy to treat Ich with salt. You’ll need a concentration of 0.3% salt (3 teaspoons per gallon) to eradicate the Ich. To reach 0.3% salt you would add 1 teaspoon of salt per gallon of water to your tank 3 times, each 12 hours apart. Predissolve the salt in tank water and then add slowly to a high water flow area.

It is important to keep track of the salt going into your tank because salt does not evaporate and is not removed with activated carbon. It is removed only with water changes. To keep the salt at the desired level, when you do a partial water change, you must salt the new water to the same concentration as the tank water. For example, if you remove 10 gallons of water you will need to add 30 teaspoons of salt to the change water to keep the tank at 0.3%.

While treating Ich, you will need to vacuum the entire bottom of the tank each day to remove any cysts that have fallen off. This will reduce the amount of tomites swimming in the tank and will help to clear the Ich faster. Heating the tank to 78-80*F will speed up the Ich life cycle and boost the fish’s immune system response. At that temperature Ich has a life cycle of 3-5 days. Typically, your fish will look like it is getting better then another wave of spots will appear. Each cycle is usually worse than the one before. But if you keep up the water changes and salt ich will clear within a week. Maintain salt at 0.3% for 7 days after the last cyst drops off the fish. This will ensure that the Ich is indeed gone. If your tank temperature is lower, the life cycle can extend into weeks so you will need to adjust your temperature or your treatment regime accordingly.

Be sure to keep your water quality excellent during this time. Ich will stress your fish so you need to ensure optimum water quality. As trophonts leave the host, they leave behind small exit wounds. That coupled with the stress suffered by the fish can give bacteria and fungi an unfair advantage, so it is important to watch out for any signs of secondary infection shortly after a bad case of ich. Here are some links that may help:

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