How to Treat Ich in Fish Tanks

Ich, or Ick, is short for Ichthyophthirius, and refers to a parasitic swimming organism that preys on fish in saltwater and freshwater environments. Ich parasites will attach themselves to a host fish's skin and feed on the bodily fluids. As the parasite feeds, it will build an outer shell that appears as small white spots on the fish's skin. Ich is difficult but not impossible to treat. Using medication in your tank that focuses on the latter thernot stage -- when the parasite breaks free of the protective shell and drops to the bottom of the tank where it will produce hundreds of free-swimming parasites -- can help to save your aquarium.

Things You'll Need

  • Aquarium net
  • Aquarium salt
  • Dropper
  • Quarantine tank(s)
  • Aquarium heater
  • Dechlorinator
  • Micron filter
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Instructions

  1. Freshwater Fish Treatment

    • 1

      Remove any affected fish from the tank gently and carefully with a net. Place the fish in a small container with only enough water to barely cover it and allow for minimal movement.

    • 2

      Prepare a salt solution by combining 2 tablespoons of aquarium salt per gallon of water. Add two to three drops of salt solution at a time to the isolated fish, waiting and watching in between additions. Cease adding salt when the fish begins to show mild distress, like difficulty breathing or erratic swimming.

    • 3

      Allow the fish to remain in this bath for about 30 minutes, carefully monitoring the fish throughout. Remove the fish and return it to fresh water if any severe stress becomes apparent.

    • 4

      Dilute the salt water bath in stages with small amounts of tank water -- half a cup to a third of a cup at a time -- after about half an hour in the bath.

    • 5

      Use a net to gently scoop the fish out of the bath and return it to the main tank, once the bath has been diluted to fresh water levels.

    • 6

      Wait 48 hours, then repeat the bath procedure with the affected fish. Complete the bath routine for up to three treatments, before allowing a significant time -- at least three full days -- to pass before beginning the process again.

    Freshwater Tank Treatment

    • 7

      Remove any gravel and plant life from the tank. Keep plants in a separate tank until the treatment process has been completed and the Ich appears to be eradicated. Clean the gravel thoroughly under running water before also keeping it separate until the treatment has been completed.

    • 8

      Increase the water temperature to between 85 and 88 degrees F. Do this in stages and only to the level tolerable by your fish. Ich is unable to reproduce properly in higher temperatures, so this method helps to stop reproduction.

    • 9

      Increase the aeration in your tank to aid the breathing of any affected fish, in case the medication can work on them. Doing this will help increase your affected fish's ability to breath as well as boost their immune system.

    • 10

      Add 1 teaspoon of salt for every gallon of water. Higher concentrations of salt will destroy existing Ich parasites by reducing their ability to maintain a proper fluid balance.

    • 11

      Change out about 50 percent of the aquarium's water daily for fresh, properly treated aquarium water. Doing so will help to eliminate free-swimming, existing Ich parasites and reduce the chances of your fish becoming infected over and over again.

    • 12

      Use a dechlorinator to help condition the water added during the daily water changes. A quality dechlorinator can be found at your local pet store and will help to seal any open wounds on your fish.

    • 13

      Switch to a micron filter in your tank's filtration unit. A micro filter will help catch free-swimming parasites, helping to rid your tank of any before they latch on to fish.

    • 14

      Purchase anti-Ich medication containing either formalin or malachite green, or a combination of the two, from your local pet store and follow the directions included.

    Saltwater Fish Treatment

    • 15

      Quarantine any fish showing strange behavior -- loss of appetite, rapid breathing, scratching on rocks or sand -- or that appear to have strange white or black spots on their bodies.

    • 16

      Lower the salinity of the quarantine tank until hypo salinity state is achieved where the salinity level reaches a specific gravity of 1.010. Do this by removing about 25 percent of the water and then adding in water with a much lower salt content every 12 to 24 hours.

    • 17

      Maintain the 1.010 gravity for a minimum of six weeks.

    • 18

      Re-introduce your treated fish by slowly adding tank water -- half a cup to a third of a cup at a time -- to the quarantine tank to acclimate your fish properly. After the quarantine tank's content is more than doubled by the addition of tank water, allow the fish to sit for 10 to 15 minutes before netting and reintroducing it to your saltwater aquarium.