Just a couple of days ago, my wife told me that one of her fish had died and the others have white spots all over them. I immediately informed her that they probably have a disease called Ichthyophthirius multifiliis, which is commonly known as ich. This is a common disease that appears in freshwater fish and it causes little white spots to appear on the outside of the fish. It’s contagious and spreads throughout the tank within a couple of days if left untreated. Ich has a 100% mortality rate if left untreated, so it needs to be taken seriously and treatment should begin as soon as you see the white dots.
What Does Ich Do?
- Will cause white dots to appear all over the surface of the fish
- The white spots cause the fish irritation and therefore stress them out
- Can lead to loss of skin which will impair the fish’s ability to control the amount of water going in and out of its body
- Will cause breathing impairments because of gill damage
- Can cause loss of vision
Ich travels from fish to fish through the water. It will attach itself to the gravel, decorations, plants, or any other ornamental item inside the tank. It will then multiply up to 10 times by binary division, thus creating more and more of the parasite. After division, the parasite will find a fish to cling to and the cycle will begin again.
The first step to treating your fish of ich is figuring out if they have the disease or not. Most of the ways to diagnose ich simply require you to look at the fish in question.
- Loss of appetite
- Rapid breathing
- Hiding / not schooling with other fish
- Resting on the bottom
- Rubbing or scratching against objects
- White dots on the skin
There are three common ways most people cure ich in aquariums, but each have their downfalls.
- Raise the temperature to 83-86 degrees Fahrenheit. This will speed up the life cycle of the ich and cause it to die off quicker. This is the most natural way to destroy the ich parasite, but it does have some downfalls. Before raising the temperature this high, make sure all of the fish in your tank will be able to withstand it. Some fish, like goldfish, prefer lower temperatures and will die if the temperature gets up to 86 degrees.
- Introduce aquarium salt to your tank. Because ich is a freshwater parasite, introducing salt to your aquarium will kill it off very quickly. You will want to make sure the salt you are adding is labeled “Aquarium Salt” and it is not intended for saltwater or cichlid tanks. For more information on how much salt to dose, see this article on the Cichlid Forums. The downfall to dosing salt is if you have freshwater plants, the salt will cause them all to die.
- Over the counter ich medications can be found at most pet stores that sell fish. If you’re using an ich medication, do a large water change (at least 40%) before administering the medication. Also pay close attention to the directions found on the medication because failure to follow them 100% accurately will cause the medication to have no effect.