Foreword:

For many years I refused to use a quarantine tank. I treated the same fish for ich and diseases over and over again, losing some old friends in the process and certainly shortening the lives of the fish that survived. Since I started quarantining new arrivals, I have had NO instances of ich or other diseases introduced into my main tanks since I started quarantine procedures.

The Equipment :

Everything in a quarantine or hospital tank should be able to withstand being disinfected. The whole point of quarantine is to be able to prevent diseases and parasites from reaching your main tanks. You will on occasion have disease in your q-tank, and some organisms can lay dormant for quite a while. Disinfection with chlorine or something similar is a must after treatment.

A small 5g or 10g tank is ideal, in my opinion. Smaller tanks limit you as to what fish you can put in there, and larger tanks are not necessary. Sooner or later you will need to medicate in quarantine, and most medication dosages are expressed in "per 10 gallons of water". An odd size tank will make the math more difficult than it needs to be.

For filtration, keep it simple and inexpensive. A small corner or hang-on-back filter is fine. You will be changing lots of water in this tank while quarantining, so extensive filtration systems quarantine is not necessary. Remember that everything may eventually have to be discarded that cannot be bleached. An HOB or sponge filter will allow you to do this economically by simply replacing the sponge.

A small heater and a thermometer are necessary for tropical fish.

Lighting should be on the dim side. Bright lights will further stress fish, which have already been traumatized by, capture and transport. However, you must be able to observe your fish, so the light must be bright enough to see ich spots (even on white fish) or changes in color. I occasionally use a small flashlight to check an individual fish.

There should be some furnishings in the tank to give the fish the feeling of being hidden. Plastic plants, ceramic or clay flower pots, even a coffee cup turned on its side, depending on the species, will give the fish a feeling of security and reduce stress.

Although admittedly a bare bottom to the tank is easier to keep clean, I use a thin layer of gravel on the bottom. This seems to calm the fish that are spooked by reflections on the bottom of the tank, particularly bottom feeders. After quarantine is over, I use this gravel to add bulk to my garden soil or provide drainage in my houseplants. I never re-use it in a fish tank. The small expense involved is more than made up by peace of mind that nothing can be passed along to the next fish in quarantine.

Another very important part of your quarantine equipment is a siphon and bucket, which is used exclusively for that tank. The effectiveness of quarantine is lost if siphons and other equipment is used in both quarantine and main tanks. It is also recommended that you care for your other tanks before you attend to the quarantine tank, for the same reason. Cross-contamination is a real concern and care should be taken to avoid the possibility of bringing infection or parasites in to your main tank on your hands or equipment.

Personally, I use a 5g plastic tank for quarantine. This is big enough for most fish for the short time they are in there, yet small enough to treat economically and observe the fish easily. I have an AquaClear Mini for filtration, a small 25W heater and a pump and airstone available if necessary. There is a rather dim incandescent bulb in the hood. Decoration consists of a clay flowerpot, a hideous but soft plastic plant, and a handful of gravel. The entire setup cost me about 35 dollars, and has served me well for years. When not needed, the entire thing is broken down and stored in a closet.

It is not necessary to use such a spare setup. I know fish keepers who keep small 10g tanks up and running permanently, fully planted and cycled with danios or barbs which they add to the main tank when a new arrival needs the space. I have found that I usually end up with fish in them permanently, as self-control in the LFS is not my strong point, so I prefer to break my quarantine tank down after each use. Plus, if a particularly virulent disease such as fish tuberculosis gets in there, the tank will still need to be torn down and disinfected.

The Procedure:

Fish should be kept in quarantine until you are reasonably certain that no parasite or illness will be transmitted to the main tank. While this is the primary reason for quarantine, almost equally important is to get the fish eating and allow it to recover from the shock of capture and/or transport without constant harassment or competition from the community. You should never move a fish in to the community until it is eating and acting normally for the species. If a normally shy fish is aggressive or a normally aggressive fish is shy, this is a red flag and the fish should be kept in quarantine until the cause of the odd behaviour is determined.

Change water in your quarantine tank on a daily basis, how much depending on the fish load. Nothing gets a fish off to a better start than clean water. A quick vacuum of the gravel or tank bottom not only removes uneaten food but also reduces any parasite load.

Medications:

The issue of whether or not to medicate as a prophylactic in quarantine is one of those debates, which has no good answer. Some feel strongly that fish should not be treated without specific symptoms showing, while others feel that treating before the fish get sick is preferable.

I tend to tread the middle ground between no meds at all and a full-out barrage. I have had many, many cases of ich in quarantine and prefer to treat with a mild anti-parasitic such as Coppersafe or Aquarisol. I am opposed to using antibiotics in quarantine unless an infection shows. We are already encountering med-resistant strains of bacteria, and indiscriminate use of them will only compound the problem

Duration :

If no meds are used in quarantine, the quarantine period should be around four weeks. With ich meds, I quarantine two weeks. You should be very quick to extend these times if any symptoms are present, the fish is not eating, or if any behavioural anomalies are noticed.

A few additional thoughts:

Try not to mix species in quarantine. Medication that will work well on one type of fish may well be toxic to another.

Try not to mix lots of fish - even of the same species - from different suppliers or stores to prevent cross-contamination. For example, a fish that came in with latent ich may get mixed with a fish that came in with columnaris. Both of these conditions are easily treatable, but together they can be deadly.

Quarantine plants, too. Ich can hitch a ride on plants. I keep mine in a fishbowl for two weeks in regular chlorinated tap water.