Tim's Tropical Fish






Curing Ich


Ich, ick or white spot disease are all names for the effects of a parasite called Ichthyophthirius multifilis.  These parasites go through a life cycle that averages about 2 weeks in duration.  Other diseases can cause the appearance of white spots too, so you can't always be certain that you are looking at ich.  It is definitely the most common disease affecting freshwater tropical fish though.  There is usually a factor which brings on an outbreak of ich.  Possible sources include poor water quality, the introduction of water caring the disease and stress to fish causing their immunity levels to drop.

Many tetras are easily stressed and after surviving a trip to a new home, their immunity levels will be reduced and they will be susceptible to low levels of ich in a tank where the original inhabitants are doing fine.  It will appear that the tetras brought the ich to the new tank, but they can actually be reacting to small levels that were already present.  Ich frequently affects tetras and clown loaches.  It can also affect many other fish, including exotic plecos.

Stage Effects
Cysts incubate in the substrate and hatch tomites
Hundreds of tomites hatch from each cyst after about three days and swim free, looking for hosts.  This is the stage when medications have the best impact.
Tomites burrow through the skin of fish, causing stress and exposure to bacteria.

General rules for treating ich:

  • Take action quickly, as ich will kill the infected fish in a few days.  It will multiple and spread to other fish.
  • Quarantine the affected fish.  This will reduce the exposure of other fish.

  • Increase the temperature a couple of degrees in the main tank and the quarantine tank to speed the life cycle of ich.

  • Change a bucket full of water out of the affected tank.  Try not to change too much water as an ammonia spike could occur and stress the fish further.

  • Use aquarium salt in the main tank and the quarantine tank.  In general most fish can tolerate low levels of salt.  We suggest 1 tablespoon for 40 gallons as a preventative measure in most tanks.  Wardley packages aquarium salt and it is sold at Walmart.  For fish showing signs of ich, try a salt bath.  For exotic plecos, our readers have suggested salt baths in a separate holding area for 5 to 10 minutes with concentrations of 4 or 5 times that in the tank they will be immediately returned to.

  • Consider a chemical treatment - more on this below

  • Be prepared to repeat the treatment.  Since ich goes through a life cycle another outbreak can occur within a few days.

Quick Cure for ich Aquarisol copper sulphate based treatment for ich tropical fish disease

There are a number of chemicals that successfully treat ich, but these are dangerous alternatives.  The cure can be more harmful than the disease with these. These treatment can be applied to the main tank and the quarantine tank.  When using chemicals remember to stop using your carbon and zeolite filters, as they will remove the chemical from the water.  Some of the common treatments are:

  • Malachite green - This is the most commonly suggested treatment.  Malachite green is a very minor but powerful ingredient in Quick Cure.  Malachite green is deadly to any fish.  It is similar to using chemo therapy in cancer treatment on humans, as it damages the fish at the same time as it kills the parasite.  Tetras do not tolerate this treatment well and it is especially hard on neons and cardinals.  Back way off on recommended dosages.  Quick Cure recommends 10 drops in a 20 gallon tank for tetras, but we recommend not more than 2 or 3 drops in a tank that size.  You can get a half drop dose by releasing a drop in a cup of water, stirring and then discarding half the solution.  For plecos the most common recommendation is to avoid using Quick Cure.
  • Formalin - Formalin or formaldehyde is the main ingredient in Quick Cure.  Novalec Inc sells formalin and malachite green separately, unlike Quick Cure by Aquarium Pharmaceuticals, which combines both ingredients.

  • Copper sulphate - This is the main ingredient in Coppersafe and Aquari Sol.  Coppersafe by Mardel Industries specifically indicates that it is safe for scaleless fish, but our readers have indicated to us that it isn't the way to go for exotic plecos.  Stick with salt and salt baths for exotic plecos.