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Treating Freshwater Ich
Ich or Ick - Better known to science as Ichthyophthirius multifiliis, and to aquarium keepers as White Spot Disease. Nearly every aquarium keeper has had some experience with this ciliated protozoan. Protozoans are very small, single celled organisms with a distinct membrane-bound nucleus. Ich is seen as large white spots on the skin and fins of the infected fish. As the life cycle of the organism progresses, cysts become more numerous and may form clusters. Each cyst contains a single protozoan under the skin of the host and at that time, it is immune from any remedy that might be used.
A single mature parasite on a fish will fall off and then attach itself to the substrate within a gel-like capsule and begin to divide. Within hours, hundreds and hundreds of immature protozoans erupt from the cyst and must find a host fish within a day or so if they are to survive. The free-swimming ciliates bore into the skin of the fish and are protected by the formation of a capsule while they mature. The process starts all over again from there and can take as little as 24 hours in water of 78 degrees Fahrenheit. At temperatures below 68 degrees Fahrenheit, the process can take several weeks.
The Ich Life Cycle
This is a video of Ich as seen
under high power magnification.
Recommended Treatment...
Treating Ich (aka “White Spot Disease”)-
The dreaded and mysterious Ich. Very few aquarists have not had experience with this little beasty at some time or another. As common as it is, you would think there would be a common consensus on how to properly treat it. There isn’t. Some diehards tout copper sulphate treatments are the only effective way to eradicate it. Other aquarists will near self-combustion if anything other than temperature manipulation is used. When it comes to the topic of Ich, the truth is, all the usual treatments work, usually with varying degrees of success.
Unfortunately, there is no one blanket treatment that will work in every situation. Milder infestations may respond to a conservative treatment (such as the raising of the temperature) while more aggressive ones might need a more severe measure, such as a chemical treatment. One thing that applies to all disease outbreaks in aquaria is there is almost always some environmental stressor that weakens the fish to the point it is prone to a disease attack. With Ich, sudden or drastic temperature fluctuations usually precede outbreaks. Check the water chemistry and dissolved metabolic wastes (ammonia, nitrite, nitrate) as well as the temperature and make any necessary changes to improve the situation. You could dump every available remedy in the tank there is, one after the other and still have no success in reducing the numbers of parasites to a level the fish’s immune system can handle because the filter is filthy, the airstones are clogged, and you haven’t done a water change in three months.
A common misconception with Ich treatments is that after three or four days, the white cysts are still on the fish, so there is the perception the treatment isn’t working.
While the cysts are attached to the fish, medications have no effect. It is only after the adult parasites (called tomonts) drop off to start the cell division before the outer capsule forms and when the tomite cells erupt from the trophont to re-infest the fish that they can be killed with chemical treatments.
S
ince this is a single-celled organism, raising the temperature raises the metabolism of it and increases the rate of its life cycle so it falls off the fish sooner and will fall to the effects of whatever chemical remedy is being used. Raising the temperature also drives the dissolved oxygen out of the water, so if you do increase the temperature, you need to significantly increase the aeration as well.
One thing most experts seem to agree on is that Ich cannot survive at temperatures of 86 degrees Fahrenheit and above. In many cases a successful control has been applied by simply raising the temperature several degrees over a few hours until it stabilizes at 86 or 87 degrees Fahrenheit and keeping it there for fourteen days or so. Most fish will tolerate such temperature increases quite well as long as you add extra aeration. Slowly lowering the temperature down (say, two degrees a day) until it is at its previous will lessen the stress to the fish.
You can also add plain aquarium salt at the rate of a tablespoon (21 grams) per gallon that will help the fish heal and clear excess mucous and cellular debris from the gills.
Keep in mind the cure isn’t affected once the cysts fall off the fish and aren’t visible to the naked eye anymore. The opposite also holds true for chemical treatments when the cysts are still clearly visible. Presence of the cysts doesn’t mean the chemical isn’t killing the free swimming forms in the water column. Many aquarists unfamiliar with the life cycle of this ciliated protozoan throw their hands up after five days because they followed directions on the package and there are still white spots on the fish. The only way you know your fish are making a recover from an infestation of Ich is just by observation. When they become more lively and intense in color, begin to swim about and hold their fins erect, you know things are getting better.
You aren’t going to be able to eliminate Ich from your system entirely; some fish have a strong immunity to it and become latent carriers with dormant cysts at the base of fins that are not visible to the naked eye. Some naysayers will scoff at this and say there is no such evidence to “dormant” forms of Ich, but they also can’t explain how it is introduced in a closed environment when nothing has been added for months and months and there is no incidence of cross-contamination (meaning a net or some other equipment was used on an infected tank and then on an uninfected one, thus introducing the disease). As with any parasitic or bacterial outbreak, the goal is to turn the tide in favor of the fish to fight it off itself and reduce the number of pathogens it has to contend with. How many times have you suddenly gotten a horrible cold after a routine visit to the doctor when you haven’t been sick all year? That’s because the concentration of disease causing germs was higher there than what your body was used to and could handle, so you got sick.
The second problem with treating Ich is there is such a huge amount of choices for chemical treatments, and new ones come out every year claiming to be better than what is already available. If that isn’t confusing enough, very few chemical (if any) treatments are safe to use with invertebrates and plants, and in some cases tank inhabitants have had adverse reactions to “safe for all fishes” type treatments even when properly dosed and administered. Metallic salts and various dyes are quite deft at killing the free-swimming phase of Ich, as well as many other protozoan nasties like Costia and Chilodonella, but they should be used with caution as they can be just as toxic to the fish if overdosed.
An old stand-by is the Malachite Green/Formalin combination which can either be used as a dip or bath, or administered to the tank itself. Be advised the biological filter may be affected by this treatment as Formalin is an aqueous solution (37% by weight) of formaldehyde, which has been used in science as a biocide (kills life) and for preserving biological specimens. Malachite Green disrupts gas exchange in cells, impeding their ability to perform basic metabolic functions, so they die. Neither one of these chemicals should be used willy-nilly nor care free, as they are quite toxic, but they do literally wipe out protozoan infestations when used correctly.
ProForm-C is a relatively new product that features both of these chemicals in a different base solution that what has traditionally been used and is purported to be more effective and less toxic than the standard treatments. It has quickly become a favorite product among pond keepers since its introduction. The drawback is it is sold in packages meant for pond use with pond-sized doses, which isn’t very practical for someone with a modest size aquarium. In that instance, you could use Aquarium Products’ Quick Cure.
Quick Cure is another Malachite Green/Formalin combination available in ¾ oz and 4 oz sizes. Malachite Green will stain the silicone a bluish-green color, so if you don’t want that to happen, you should opt for the temperature elevation/salt tonic treatment or use a copper sulfate (one of the aforementioned metallic salts) treatment. Weco Products’ Nox-Ich is another old stand-by for treating Ich and works very well. It is a Malachite Green/Sodium Chloride solution, which will also stain silicone. It has been used for decades to treat protozoan infestations in aquarium settings, so if you don’t mind the nice bright blue patina on your silicone, have at it.
Copper-based concoctions are also very effective at killing protozoans, but they must be administered correctly and tested as instructed by the manufacturer.
Ionic copper at levels above .20 ppm for an extended period of time can be toxic to the fish, and are always toxic to invertebrates. Plants and nitrifying bacteria don’t like it much either, which is why many copper sulphate treatments are performed outside the main aquarium in a hospital tank. The temperature in the main tank is elevated to above 86 degrees Fahrenheit and left that way for a week or so until the majority of resting/dividing cysts in the tank hatch out in search of a host and die within a day or two because they can’t find one since all the tank residents are in the hospital tank. Chelated copper solutions (such as Mardel’s Coppersafe) are also widely available, although their effectiveness is often questioned in aquarium circles because there really isn’t anything safe about meetings between aquatic life and high levels of metallic salts; ones that are said to be so might not be that effective. Still, many a tank has been relieved of parasitic infestations with such products and chelated copper solutions have just as many supporters as they do detractors.
Before treating an aquarium with any chemical, you should perform the following tasks for best results. If you are doing the bath method, you should also do these just as a check up and to improve conditions in the tank.
- Give the aquarium an equipment check. Inspect the heater, air pumps, airstones, powerheads, pumps and filters to ensure they are working properly. Disease breakouts are always preempted by a bout of stress, which is almost always attributed to water quality.
- Make sure all fish are present and accounted for. Check under rocks for missing fish, since that is usually where they can be found after they expire. Remove any carcasses and discard.
- Test the water so any waste management issues can be addressed. Elevated levels of ammonia and nitrite contribute greatly to the weakening of the fish and the presence of disease.
- Change 25% of the aquarium water with a gravel siphon (even if test results don’t indicate elevated levels of ammonia or nitrite), removing as much detritus as possible, and refill with water of the same temperature and pH as what is in the aquarium. Be sure to treat tap water with the appropriate dosage of dechlorinator/water conditioner. Reducing the amount of organic waste in the tank increases the efficiency of medications, particularly organophosphate-based ones used for treating parasites. It also helps remove the egg sacs and developing cysts of parasites that have settled in the gravel.
- Increase aeration in the aquarium by adding a second air pump and a few airstones. Diseased fish have a harder time performing gas exchange in the gills (osmoregulation) and need all the help they can get.
- Remove any activated carbon or resin-based filtering products for the duration of the treatment, but keep the filter floss in place.
- Shopping List
- ProForm-C
- Aquarium Products’ Quick Cure
- Weco Products’ Nox-Ich
- Mardel’s Coppersafe