MYTHBUSTER: ALL the well-done scientific studies by researchers on heat and ich have found heat to be totally ineffective in treating ich!
Note there are two other diseases that look like ich (tetrahymena in livebearers and epistylis in other fish). So make sure you have ich.
Public Aquariums use formalin/malachite green (Ich-X, Rid-Ich Plus, Blue Planet White Spot Remedy, AquaCare Anti-Fungus & White Spot, and Mardel QuickCure) to treat ich in freshwater fish, as do University Research Centers, Cory of Aquarium Co-op, and Joey.
- NEVER turn off the filter, remove the filter, change the filter media or clean the filter media. If the carbon has been in the aquarium for more than two weeks do NOT remove it (contrary to some directions). This is VERY important.
- Do NOT move the fish to a quarantine tank (contrary to some directions).
- Formalin and malachite green are both toxic in large enough dosages so carefully follow the dosage directions on the medication bottle.
- If one raises the temperature with formalin/malachite green the medication can become somewhat toxic.
- Cory and others have treated thousands of “scaleless” fish with full strength formalin medication with absolutely no problem.
- Formalin/malachite green is not poisonous to snails or shrimp at the proper dosage.
- At 76 degrees formalin and malachite green need to be added every day to be effective.
- Follow the directions on the medication as to water changes.
The seminal study on ich treatments (Tieman and Goodwin, 2001) found salt (0.25%) and heat to have no effect on ich. Other studies say 0.5% to 1% salt can reduce mortality from ich but is not as effective as medication. UV sterilizers, even at low wattages, can help immensely to eliminate ich from the aquarium.
Established filters have thousands of little carnivorous critters in them which eat the infectious ich stage (the “theront”), so the filter is very important. The net result of this filter “medication” is that if you have a long-established aquarium filter with plenty of brown “gunk” in it, it is perfectly OK to do absolutely nothing for the ich. It will simply go away on its own in a week or two.
Because ich will go away in an established aquarium, there are at least 55 “treatments” currently “absolutely guaranteed” to stop ich. There is an old saying in science: “correlation does not imply causation”. ANY treatment of ich in a tank with an established filter will work. The ashes from the cremation of a dead squirrel will work to remove ich in a tank with an established filter
One Facebook commentator had ich pop up. He set up an “emergency” hospital tank with a new filter and put the infected fish into it. He took the temperature up. He added some salt. All the fish died. Not a good idea! The lack of microscopic carnivores in the new filter let ich kill the fish.
Several Facebook commentators said things along the line of:
“I set up a new tank per the instructions of my LFS and added Prime conditioner, Stress Coat and Stability. Per the instructions of my LFS I added six platies, four neons, and two angelfish. They all got white spot disease. So I added Melafix medication per the instructions. All my fish died. Where did I go wrong?“
Again, the lack of microscopic carnivores in a new filter (and using Melafix as the medication) doomed the fish. This is one very good reason to do fishless cycling for four to six weeks before adding fish. Note these deaths will always be blamed by the experts on “ammonia poisoning”.
Ich Treatments with Research which Backs Them
There are six treatments which have valid university research backing them as decent treatments for ich (in descending order of effectiveness):
- PREFERRED TREATMENT FOR FRESHWATER – Formalin/Malachite Green (Ich-X, Rid-Ich Plus, Blue Planet White Spot Remedy, AquaCare Anti-Fungus & White Spot, and Mardel QuickCure)
- Malachite Green alone (API Super Ich Cure, Nox-Ich, Tetra Ick Guard, Kordon Rapid Cure, Costapur by Sera, Paraguard, Waterlife Protozin [malachite green and copper] or Waterlife Myxazin [Malachite Green and Acriflavine])
- Formalin (NT Labs Koi Care Formaldehyde)
- Copper (Cupramine, Copper Power, Copper Aide, ESHA 2000 or Copper Safe)
- Methylene Blue (Kordon Methylene Blue)
- 5,000 to 7,500 ppm salt (sodium chloride)
These are the ONLY medications with any university backing. Note there are over fifty other medications claiming to be effective.
The seminal study on ich treatments (Tieman and Goodwin, 2001) found salt (0.25%) and heat to have no effect on ich. Other studies say 0.5% to 1% salt can reduce mortality from ich but is not as effective as medication. Adding a wavemaker and/or a UV sterilizer is also very helpful in treating ich.
Established filters have thousands of little carnivorous critters in them which eat the infectious ich stage (the “theront”) so the filter is very important. The net result of this filter “medication” is that if you have a long established aquarium filter with plenty of brown “gunk” in it, it is perfectly OK to do absolutely nothing for the ich. It will simply go away on its own in a week or two.
Also note that both copper and salt CAN kill SOME plants. There is no research on what plants are or or not affected. At proper dosages formalin/malachite green does not normally kill plants.
Using Formaldehyde/Malachite Green to Treat Ich
The medication of choice for home aquarium is unquestionably formaldehyde/malachite green. Products such as Ich-X, probably the most popular ich medication in the hobby, are formaldehyde (<5%), methanol (<2%), malachite green chloride (<0.1%). If Ich-X is used per the directions, it ends up being 22 ppm of formalin and 0.13 ppm of malachite green in the aquarium.
One interesting myth is that if a bottle has a filmy white mucus in it when it is opened do not use it as this mucous is deadly. The mucous is polymerized formaldehyde, a plastic material known as an “acetal polymer”. It is harmless. But the solution has lost its effectiveness and should be discarded. The methanol in Ich-X is there to stabilize the formaldehyde against this polymerization. Cold temperatures accelerate the polymerization.
Note that many, including the medication manufacturers, do not understand the importance of a filter to the removal of the infectious ich theronts. Typifying this is the Ich X directions per Hikari:
DIRECTIONS FOR USE
To treat “ich” disease (ichthyophthiriasis) of freshwater fishes and “marine ich” disease (cryptocaryonaisis) of marine fishes, add one (1) teaspoon (~5 mL) of Ich-X to 10 gallons of aquarium water. For Best Results: (1) always treat in a separate quarantine/treatment tank, (2) remove activated carbon from filters and clean or replace mechanical filtration media (do not stop filtration!) (3) make at least 1/3 water change before each addition of Ich-X (use Ultimate to condition new water (4) repeat treatments at least every 24 hours, but no more often than every 8 hours, depending upon the course of the disease (refer to the Ich-X Product Data Sheet).
We do NOT recommend transfer to a hospital tank with a new filter. One must have an established filter to treat ich. We do NOT recommend replacing mechanical filtration media as in most aquariums the “mechanical filtration media” is actually biological filtration. We do NOT recommend cleaning the filter or removing the activated carbon. In most aquariums the activated carbon in the filter is long overdue for change and will not remove the malachite green.
In 90% of the aquariums using activated carbon the carbon is just a biological media covered in beneficial bacteria. The activated carbon has become “deactivated” carbon and simply acts as a surface where the microscopic carnivores that “eat” ich theronts can multiply.
If one is in Europe formalin is not available. There are three medications which will work in place of formalin/malachite green: malachite green, methylene blue and copper (Cupramine, Copper Power, Copper Aide, ESHA 2000 or Copper Safe).
If one is dead set against using any “chemicals” in their aquariums and wants to use a “natural” approach, salt (sodium chloride) is reasonably effective at a dosage of one to one and one half cups of salt per ten gallons of water (5,000 to 7,500 ppm). Note research says this is NOT as effective as the medications above. Note that this level of salt will kill most plants. Adding a wavemaker and/or adding a UV sterilizer will also decidedly help control an ich outbreak.
To go into the research on ich medications click on the following link:
10.2.2.4. Ich Medications in More Detail
Ich in more Depth
Ich is the most common fish disease and warrants a more in-depth discussion. The following chapters are devoted to this common fish disease:
10.2.2.1. Ich in More Depth
10.2.2.2. Immunity of Fish to Ich
10.2.2.3. Ich Medications
10.2.2.4. Ich Medications in More Depth
10.2.2.5. Ineffective Ich Medications
10.2.2.6. Using Filtration to Remove Ich
10.2.2.7. Treating Ich with Heat
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Return to Ich Menu
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