How to Kill Ich in a Fresh Water Fish Tank

Ichthyophthirius multifilis, or Ich, is a parasitic infection that affects aquarium and pond fish. It is also known as white spot disease, because it causes white dots all over the body of an infected fish. Ich can infect cold water and tropical freshwater fish, and can infect fish tanks through the addition of new fish, live plants and live food. In addition to white cottony body spots, infected fish may seem lethargic and clamp their fins. If left untreated, ich can prove fatal to your pet fish. Use natural and chemical treatments to immediately treat your freshwater fish tank because ich affects the entire aquarium.

Things You'll Need

Aquarium salt or marine salt
Malachite green and formalin
Micron or diatom filter

Instructions

- 1
  Increase the temperature of the water in your fish tank to destroy ich and retard reproduction and growth. Gradually raise the temperature by 1 degree each hour, to 86 degrees for a period of 10 days, as freshwater tropical fish can tolerate this temperature. Reduce the temperature of the aquarium to its original temperature by 1 degree per hour.
- 2
  Add aquarium salt or marine salt to the fish tank. Salt disrupts the fluid regulation of ich and destroys it. Use a ratio of around 3 teaspoons of salt for each gallon of tank water. In a bowl, thoroughly dissolve the salt in a little tank water and gradually add it to the fish tank over a period of two days. Once the ich has cleared, remove the salt through a daily water change of 25 percent.
- 3
  Combine malachite green with formalin to treat moderate to severe ich infestations. Use the recommended dose on the package to treat fish. However, for sensitive fish species such as piranhas, neons, sunfish and some scaleless fish, use half the dosage strength to reduce stress to these fish.
- 4
  Install a micron or diatom filter in your fish tank. These filters will clean the fish tank by removing free-swimming ich and other bacteria.