A "true" quarantine tank

by Francesco Zezza

Quarantine means keeping a fish (either a sick one or a "newly acquired" one which needs to be closely observed for some time) in a secluded area (tank) to be sure that : a) they’re recovering and/or b) they are NOT carrying any (possible!) pathogens. In its everyday meaning the term "quarantine" means keeping an animal (but under given circumstances also a human being) in isolation to prevent spreading of possible diseases. Ok now, that’s clear but … what about me? Why I’m supposed to keep and run a quarantine tank ??

Be patient, please! We’re going to explain this in a while …

To start with, how does a real quarantine tank look (better still: how should it look like)? I feel this issue is more or less clear, nevertheless I would like to clarify some main points which could help newcomers (although - in my opinion - newcomers are not the only ones who should read this). Have you ever experienced the spread of a disease immediately after having introduced a new - just bought from a trustworthy fish shop – fish to your tank without taking any precautions in advance? If this has been the case even once, you know perfectly well why a quarantine tank is a REAL need!!!

Let's move on to the basics - or not so basics.. To answer the questions "how should it look like" I would say that it should be characterized by the absence of any true aquascape with a sand layer at the bottom (it should be a very thin layer and the size of the grain should be the smallest possible - better still leave it without any substrate), perhaps a couple of plants which will make the fish feel more comfortable while hiding spots are – of course – a MUST. These can consist of a couple of bogwood pieces and/or flowerpots that - by the way - are easy to clean and disinfect ! You should always be particular careful to check the condition of your filter(s) to be sure that they are in top notch condition. This may sound a bit "elementary" but - you can take my word for it - it helps. An air-stone will usually help (especially if the tank is to be used for the treatment of a sick fish).

Personally, I would go for something absolutely minimal consisting of one (or two) pieces of bogwoods, a very thin layer of sand, the filter, heater and air pump and finally, subdued lighting (if any at all). You should keep in mind that some medicinations are light sensitive (like tetracycline, minocycline etc.). I would also like to note my preference for glass against acrylic. Glass is quite transparent, far more resistant to scratches, easy to clean and disinfect and finally, a material you can work with yourself.

The filter unit will, most likely, rely on a water pump (the other option being a "sponge filter" driven by an an air pump) and should be loaded with synthetic wool-like floss, ceramic pipes and other media according to the specific needs of the fish or the medication. Always use oversized filter units and never use activated carbon since it will quickly adsorb the medication(s) in use. If you have to set up a quarantine tank on the spot due to an unexpected emergency, it would be a good idea to add some filter media from the filters running in other - healthy - tanks. Beware of possible nitrate/nitrite spikes in your quarantine / hospital tank since many drugs – e.g. most antibiotics – will also affect the beneficial bacterial colony in your filter. A separate heater is a must in a quarantine tank and it should be larger than anticipated since you may have to raise the temperature substantially during the treatment (e.g. in Ich infestations). Finally, if you have to run more than one quarantine tanks at the same time (I had to run three of them at some point), you should NEVER use central filtration since this distribute the problems from one tank to the others. Then:

Tank size? Is - of course - directly related to the size of fish you plan to quarantine; any way – again as a general rule of thumb – "think small": many drugs are very expensive ! Most likely a 40-80 (or even 100) liter unit should work with almost all fishes.

You don’t have a – quarantine – tank? Not really a problem. A plastic bucket will, perfectly, work as a quarantine tank. I have personally used a plastic bucket as a breeding / isolation tank for a Labeotropheus female. There were no lights and no heater in the bucket (this took place during the summer months) - just an extremely small filter, since carrying M’buna don’t eat (almost at all) and produce, almost, no wastes. The whole operation was successful : I got 23 fry!!!
Where do I have to put my quarantine tank? It’s up to you: only requirement is a calm, silent place to keep the stress of the fish to a minimum.
What about water change? The optimum will be 25% (of gross water volume) on daily basis. If this is too much for you than just keep in mind that the more water changes (both in terms of volume and frequency THE BETTER! Avoid continuous flow tanks since water flow will "dilute" the medications and result in the wrong treatment. In this case it is imperative to know how much water you have changed in order to replenish the medication removed.
Any "safety tips" for tools (such as hand-nets)? There is only one rule and an extremely simple one: never share tools, of any kind, used in quarantine / hospital tanks with any other tank This will allow you to to prevent any possible disease(s) from reaching the rest of your tanks.
Tank-mates? I’d say NO! This is only allowed if you are quarantining two (or more) compatible genus/species at the same time. Even in this case, if you can avoid it, you better do.
Time spent in quarantine unit? About 4 to 6 weeks (possibly shorter if dealing with aquarium bred fish from a trustworthy source) should allow a clever fish-keeper to detect any illness. Should a problem arise during the quarantine period you will have to extend it accordingly. The aim is to have a period of 4 to 6 weeks withour any disease problems in the quarantine tank. Only then you can safely (meaning: with minimized risk) add the fish in their final tank.
Switching to main tank? A few days before the moving the quarantined fish start changing the water in the quarantine tank with water coming from the main tank to allow the newcomer(s) to get gradually used to to the actual water chemistry of the main tank unit. Also make sure that the temperature in the two tanks is exactly the same. Checking as many parameters as possible will help (pH, GH, KH, nitrates etc.)

PERSONAL TIP? Force yourself to observe - on a daily basis – your new fishes to get used to their temper, living/feeding habits and the alike which will render you able - just in case (knock on wood!) - to spot any signs and symptoms of illness on the spot and take action immediately. Keep in mind that a fish, even in a quarantine tank will always act according to his/her own genomes: an aggressive/territorial cichlid will act accordingly so be very conservative when stocking your quarantine tank.