How to Treat Marine Fish With a Cloudy Eye

Cloudy eye in saltwater fish is characterized by a whitening or cloudiness of their eyes and is most common in newly introduced fish. The condition is most likely the result of a bacterial infection, though at times it can stem from a fungus. Treating cloudy eye is a several-step process that involves the isolation of the fish, the subsequent treatment with chemicals and adding certain vitamins to its diet.

Things You'll Need

  • Quarantine tank (10 gallons)
  • Premixed saltwater
  • Aquarium heater
  • Hanging filter
  • Hydrometer
  • Fish net
  • Antibiotic (tetracycline, chloromycetin or Sulfadimidine)
  • Fish vitamins
Show More

Instructions

  1. Quarantine Setup

    • 1

      Set up a quarantine tank using premixed saltwater, available at pet stores. The tank should have an aquarium heater set to around 82 degrees Fahrenheit, a standard hanging filter and no decorations whatsoever (you don't even have to include gravel).

    • 2

      Dilute the water in the quarantine tank with fresh water until it reaches a salinity level of 1.011 to 1.012 ppm (parts per million, the amount of salt in the water), which can be measured using a hydrometer. Fill the hydrometer with water from your tank, place it on a flat surface and then wait for the floating needle to point to the specific gravity (salinity).

    • 3

      Remove any carbon from the filter. The activated carbon simply removes any antibiotics you place in the water later.

    Treatment

    • 4

      Transfer the infected fish to the quarantine tank from its primary tank using a fish net.

    • 5

      Add the proper dosage of antibiotic to the tank. The antibiotic comes in either a liquid form or capsule form. If it is intended for freshwater fish, add a double dose. Apply the antibiotic every day for three days.

    • 6

      Perform a water change after three days of dosing. You are not able to change all the water, but you should be able to change at least half of it depending on the size of your fish. A water change can be performed with buckets and the premixed saltwater, which you should dilute to the appropriate 1.011 to 1.012 ppm before adding it to the quarantine tank. Water changes ensure that bacteria are slowly eliminated from the water.

    • 7

      Repeat Step 2 and Step 3 until the cloudy eye is eradicated and the fish looks normal and healthy.

    • 8

      Raise the salinity level in the quarantine tank gradually over the next two or three days using the premixed saltwater until it reaches the level of your primary tank. When the levels match, you may transfer the fish back to its primary tank.