(The following article was originally posted as a discussion thread on Reef2Reef by Humblefish. But it is so helpful and well done, R2R staff has turned it into an article)

The purpose of this article is to discuss the pros and cons of ich eradication and ich management and present the best methods for implementing each. (Ich - a protozoan disease - is the most common disease of all freshwater and marine aquarium fish.)

Ich Eradication
Simply put, this means doing everything possible to keep ich out of your tank. That can be accomplished by establishing and maintaining a strict quarantine (QT) protocol as outlined here: How to Quarantine.

A photo of Humblefish's QT tank. If you want to avoid ich - quarantine!

It is very important to QT each and every fish - including your very first one - if you wish to avoid ich.

Why practice ich eradication? Once introduced by an infected specimen, and so long as there are always fish to feed on, ich can survive in your tank almost indefinitely. The only way to get it out is to starve it out by going fallow (fishless) for 76 days. The ich parasites continuously attack (feed on) fish, which does damage and can even kill them. I personally chose ich eradication, because I got tired of “ich management” being a part of my aquarium husbandry. There’s enough to do in a reef aquarium on a daily basis without adding “battle fish parasites” to the list.

The cons of ich eradication are somewhat obvious. In addition to having to setup and maintain a QT, not being able to add your newly purchased fish directly to the display tank (DT) can be a major buzz kill. QT does zap some of the “thrill” out of the hobby.

What if I already have ich in my tank? There is no easy way of dealing with this. You have to catch all of your fish. Then you have to QT/treat using copper, Chloroquine phosphate, tank transfer method or hyposalinity. More detailed information on all the aforementioned treatment options can be found here: Treatment Options Index.

After you've gotten all the fish out and are working on the QT/treatment, the DT itself must be left fallow (fishless) for 76 days to starve out any remaining parasites. Corals/inverts cannot host, so they can be left in the DT during the fallow period. You must be wary of cross contamination during the fallow period, avoiding anything wet (including hands) when going from QT to DT (or vice versa). “Aerosol transmission” is another concern, so it’s best to house your QT at least 10 feet away from the DT. More info on that here: Aerosol transmission.

Remember there is no “reef safe” ich treatment that actually works! Traditional medications used to treat ich can harm and kill your corals and invertebrates. Supposedly "safe" natural treatments may or may not help fish with their symptoms; but no tea tree oil from India or garlic extract or any other herbal/natural “medication” will completely eradicate ich from a tank. The day someone does finally develop an effective “reef safe” treatment, we are all going to hear about it, and the inventor will become a millionaire.

Ich Management
This method involves just managing the presence of the disease, instead of eradicating it. You know you have ich in your tank or are willing to risk it by forgoing QT. Despite how strongly I advocate ich eradication these days, I employed ich management for almost 30 years. I found the key to success with ich management was keeping the overall number of parasites down, while simultaneously boosting the fishes’ immune systems to deal with the parasites that survived. Some ways to accomplish this “immune system boosting” include:

  • UV sterilizer/diatom filter: You can boost your fishes' immune system by using the biggest UV sterilizer you can fit/afford. While a UV will probably never “zap” all of the free swimmers (theronts), it will keep their numbers down so the fish can better cope with the ones remaining. A diatom filter can also be used to remove free swimmers. (“Free swimmers” means the little ich parasites that are swimming around “free” in your tank.)

  • Proper nutrition: You can (and should) boost your fishes’ immune systems through proper nutrition. This means feeding a wide range of live and frozen nutritious foods, not just flake and pellets. Feed nori, as that is loaded with vitamins. Also, soak fish food in vitamin supplements such as Selcon, Zoecon and Vita-Chem to further enhance health. Omega 3 & 6 fish oils are great (and cheap) soaking alternatives.

  • Good aquarium husbandry: Stay on top of your aquarium husbandry! Maintain pristine water conditions, stable parameters and avoid fish that are likely to fight. Poor water quality, fluctuating parameters and aggression from other fish may “stress” a fish out, lower his immune system and make him more susceptible to parasitic infestation.

  • Choose your fish wisely: Avoid “ich magnets” (i.e. fish with thin mucous coats such as tangs). Clownfish, anthias, wrasses and even mandarins are better choices, as those have thick slime coats that protect their skin from attacking parasites. Also, only buy from reputable sources, and don’t buy fish that look diseased/damaged, won’t eat or who share water with diseased fish.

  • Garlic (debatable): No discussion of “ich management” can be had without mentioning garlic. This topic is often debated, and I honestly don’t know whether or not soaking garlic in fish food helps with ich. I have seen it work as an appetite stimulant, so that might help right there. However, I’m less confident in its ability to boost a fish’s immune system. Another theory is that garlic leaches back out of a fish’s pores, and that makes the fish an undesirable host for parasites. While there is no scientific evidence supporting anything beneficial, studies have been done linking long-term garlic use with liver damage in fish. Therefore, I use garlic sparingly.
A fine example of utilizing proper nutrition to keep the bugs away is Paul Baldassano’s (aka Paul B) over 40-year-old, 100 gallon aquarium. Paul keeps his fish in “breeding condition” by feeding live foods (ex. blackworms) and soaking food in Omega-3 fish oil. Most of his livestock live to be a ripe old age, and some of his fish spawn on a regular basis. I have a tremendous amount of respect for Paul and highly recommend this article written by him: Reefkeeping Magazine - Paul Baldassano?s Reef - 40 Years in the Making.

This poor guy (and his owner) is dealing with the dreaded ich. Tangs, with their thin mucous coats, are especially susceptible.
tangich resie.jpg

Pros & cons of ich management:

One upside of practicing ich management is obvious; not having to QT. I get it; I really do. It’s exciting to make the rounds of the local fish shops, finding that “perfect fish” and then adding him to your DT. After all, having fun is what a hobby is supposed to be all about. What’s fun about adding a fish to a bare bottom QT with PVC elbows?

However, the downsides are numerous. All it takes is one “stressor event” to undo years of ich management. By stressor event, I mean something like a prolonged power loss, heater sticks, fish fighting, etc. - anything that stresses a fish out and lowers his immune system. Sometimes ich capitalizes on these events by overwhelming a fish’s immune system, and fish start dying. Also, secondary bacterial infections are common in fish afflicted with ich, due to their already compromised immune system. All it takes is a cut or an open wound left by an ich trophont. These bacterial diseases sometimes prove to be far deadlier than ich itself, especially if caused by a gram negative bacterium.

Ich management is more of a “learn as you go” process, which is why experienced hobbyists often fare better than newbies. For me, ich management just got to be too stressful. The stress of seeing the spots, wondering if today was going to be the day it finally caught up with me, or if the fish that just died was a result of ich or something else. Losing too many fish under “mysterious” circumstances is what finally led me to choose ich eradication.

Last edited: Aug 20, 2016