The Who, What, When, Where, Why and How of Quarantine

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Educated Idiot
Dec 15, 2004
San Angelo, TX
The topic of Quarantine Tanks (Q-tanks, Hospital Tanks, QT tanks) comes up on the boards quite often and I am always surprised by the number of people that don’t employ them on a regular basis. I’ve heard all of the regular excuses from lack of funds, lack of space, lack of cooperation from significant others to the ever honest lack of concern. Frankly, none of these excuses fly well with me and so I am hoping that if you give me a few minutes of your time, that perhaps I can convince you of the ease, inexpensiveness and downright necessity of employing the use of a Q-tank in your home.

Who should use a Q-tank?
Everyone that has at least one fish tank. It really is that simple. If you have a main tank and ever plan to perhaps purchase another fish to add to that tank or to treat a sick fish, then you need a Q-tank. If you have fish in a main tank that are exposed at all to any kind of bacteria, virus, fungus, parasite, nematode or anything else (by the way, if you have fish in a tank, they are open for these things unless you take extreme precautions) then you can benefit from proper and regular use of a Q-tank.

What is a Q-tank?
It is a tank in which you can treat and observe newcomers to your tank. Those of you with roots in Latin languages may well recognize the roots of Quarantine. It is derived from 40 days. For fish I feel you can cut that back to 30 days. 30 days of quiet time for any newcomer(s) should be sufficient to get them used to the environment you provide your fish. It gets them adjusted to your source water. It gets them adjusted to the lights, sights and sounds in your space. It also grants you, the fish keeper sufficient time to observe the fish without the social interaction of a community of fish. You can learn the fish’s mannerisms and behaviors. This will help you down the road to recognize if something is wrong with the fish. Knowing a particular fish’s habits should never be underestimated as a diagnostic tool. Also, 30 days is generally enough time to get a clinical diagnosis of certain ailments common to fish. So, in essence, a Q-tank is a buffer zone for the new fish, yourself, and all of the other potential tank inhabitants with which this fish may come into contact.

When should I use a Q-tank?
Always. Anytime you bring home something new to put into your tank you should use quarantine. Anytime you see a sick or injured fish in a main tank you should use quarantine. The reasons are simple. By using quarantine every time you significantly lower the chances of cross contaminating your general population. By using quarantine every time you significantly reduce the amount of medicine you would have to dose in a larger, more occupied tank. By using quarantine you will know your fish better and the importance of that should not be overlooked.

Where should I put a Q-tank?
Opinions will vary here, but obviously some conditions are better than others. I prefer to have a Q-tank near my main tank. This way transfers are easy and conditions are likely to be comparable as far as lighting, temperature and source water are concerned. Also, keep in mind that observation is so important to QT that the Q-tank needs to be someplace where you are likely to spend some time studying it. What good is it to have a QT in a spare bedroom in which you spend no time? When your Q-tank is not in use, you can simply keep it stored somewhere out of sight, but still handy enough to get to when you need it. Having a Q-tank that is in a storage building or in a shed outside where it is not only out of sight, but out of mind obviously doesn’t serve the purpose. I keep mine in an interior closet or on the bottom shelf of the stand of my main tank when not in use and on the bottom shelf of my main tank stand when it is in use.

Why use a Q-tank?
By now you’ve already heard some great reasons, but let me summarize them here for the sake of completion.
  • It is cheaper to dose meds in a smaller Q-tank than a larger community tank.
  • It removes fish from a community environment. This is important for new arrivals, mothers who birthed recently, and obviously the other tank inhabitants when it comes to communicable disease.
  • It keeps the bio-filter in your main tank safe from medicines that may harm or even destroy it. Antibacterials can kill your beneficial bacteria. Who wants to cycle a tank with a full bio-load and treat an illness in a precious main or show tank?
  • It provides you with important observation time to get to know the behaviors, mannerisms and personality of your new charge(s). I cannot place enough emphasis on this. How can you tell if one of your animals is sick if you’re not even really sure how he acts normally? Oftentimes fish show little to no warning or indication other than lethargy, irregular feces, rapid breathing or clamped fins. If you’ve not observed an animal for a sufficient time, you may have a hard time recalling if that one fish has ever had a normal bowel movement, not breathed hard, or not gone to the bottom to rest every once in a while.
There are so many threads here at Aquaria Central and dozens and dozens of message boards just like it with people posting and asking if their fish is sick. Do you think that if more people spent a good 30 days observing a fish that they might be more comfortable in diagnosing for themselves what is abnormal for their fish? The truth of the matter is that since it is your fish and your responsibility and since no one else can see the fish but you that the best chance at an accurate diagnosis is going to come from knowing your fish. For instance, my albino corydoras will lurk in the corner much of the time, but my peppered corydoras are nonstop plant leaf scavengers. If I hadn’t taken the time to get to know them this way, I might be posting asking people to help diagnose my sick cory and then be treating them with harsh medications because of someone’s best guess at why they are “lethargic” when really, they’re perfectly healthy. And believe me, meds can kill fish. In my mind, it is irresponsible ownership to not know one’s fish. Okay, enough on that, you get the picture. Q-tanks save money, time, worry, hassle, fish’s lives and your sanity. So, to me the question is not so much why, but why not have a Q-tank?

How do I set up and use a Q-tank?
I’m glad you asked! First things first, you need to decide on the size of the tank. If you keep a lot of larger fish, then a larger Q-tank is necessary. If you keep most of the “normal” smaller tropicals and have an average sized tank, (I think we can agree that most fish keepers fall in the range of 10-55 gallons of tank since those are the easiest and cheapest to come by) then a 10 gallon tank may be all you need. A ten gallon is nice because it makes math simple for dosing meds a simple matter and can house most small tropicals. Keep in mind also that most new fish sold in pet shops are juveniles and sub adults, so a smaller tank is okay. I use a 10 gallon myself because I house small tropical fish and nothing with an adult size over 4 inches long. So, I’ll use that as my example tank. So we have a tank that is roughly $10.00. Now we need filtration.

You can go any number of ways with a filter. If you have the money and use multiple BIO-Wheels on a main tank, obviously a BIO-Wheel equipped power filter on a Q-tank could be desirable since you’d always have a cycled BIO-Wheel ready to roll. Having cycled media is of the utmost importance with a Q-tank. I’m cheap. I don’t mind admitting that. So, I use a sponge filter. I simply slide the sponge over a filter intake of one of my main tanks power filters to keep a nice flow of water through it to encourage bacterial growth. If it gets clogged or otherwise impedes flow, a quick jiggle under some tank water that I have removed during weekly maintenance is enough to clean it out, yet not damage the beneficial bacteria adhered to it at all. If you have a canister filter, you now have a use for all of those extra media baskets that you stared in wonder at when you first set it up. Toss a sponge in there.

Also, always have an extra sponge, BIO-Wheel or other media on hand. If you treat something particularly nasty it sometimes becomes more prudent to dispose of old media than to try and reuse it. When I want to set up the Q-tank, I get the water in it, the filter set up and turned on and then add a new sponge to my main tank. This way it begins seeding right away and is ready in case I have to ditch the old one.

I like sponge filters because I can use the old standby air pumps for them. The major disadvantage I see to power filters and canisters on a Q-tank is that their cost to operate is a bit higher and if you need to chuck old media, it’s much more expensive than just replacing a simple sponge. You can even make your own sponge filters. Just do a search on Google for DIY Sponge Filter. You’ll find many easy and cheap designs out there. So, you have a filter for your 10 gallon Q-tank and the air pump to control it. Filter cost, if buying a decent name brand filter with an extra sponge and an air pump, $15.00 maximum. Remember to check around for old air pumps and look into DIY sponge filters. They are easy as all get out to make. You could get out of this step with a friend’s old air pump that’s not in use and a homemade filter for less than five bucks.

Now you need some of the basics. A 50 watt heater, a thermometer, a net, some type of cover (and this doesn’t need to be anything expensive or fancy; a piece of scrap glass cut to fit your tank top works,) and maybe a light, if you think it’s necessary. A lot of treatments will call for a light to be turned off and newcomers will often appreciate the subdued lighting of just ambient room lights to the brighter aquarium lights. Also, I like to use a bit of gravel on the bottom of my tank, along with a plethora of fake plants and some clay pots for hiding places and to ease the stress. Remember, the point of a Q-tank is to keep a main tank out of harms way. I do not suggest sharing equipment between the two. if you do, please remember to boil and or bleach and allow to completely dry anything that goes into the Q-tank and should go back into the main tank. I ordered most of this stuff from Big Al’s Online in an order of regular fertilizers and water conditioners for my main tank. I estimate the cost at around $15-20. I like plastic plants and clay pots because they are easy to bleach. Again, with a Q-tank I want ease of use and inexpensive to operate, so being able to bleach if I have a fish with the fishy equivalent of the bubonic plague is a nice luxury. None of this stuff needs to be top of the line. Check clearance sections. Buy neon plants if they are on sale, fish don’t care. ;)

Many people do not use gravel ni their Q-tanks. That is fairly common, but I and others feel that fish do better with a substrate instead of a bare bottom. They seem to spook sometimes in a bare bottom tank. I also suggest a plain black or dark blue background. It helps the fish stand out better for observation and soothes them.

So, considering the maximum allotted amount for each item or set of items you are looking at ~$45.00 to set up a Q-tank. Many folks can find tanks, stands, air pumps, plastic plants etc. in their own garages, other folks’ garage sales or in the classifieds for little to no money and effort. If you are picky and want top of the line gear and lighted hoods and such, you can still probably get a Q-tank for $60.00. For most of us with fish, that’s a pretty minimal investment compared to show tanks. Heck, my lights for my 29 gallon planted tank cost me more than $60.00 after shipping.

How to use a Q-tank is simple. As I said, keep media ready to go in another tank. When you get a new fish or see a fish acting strangely, dig out the Q-tank, give it a rinse and get it up and running. Acclimate the fish like you normally would and then drop it in. Some people use a salt dip in a transfer bucket before QT, and then use some form of prophylaxis during QT, but that isn’t germane to this article.

During the first 48 hours, only treat for obviously visible disease. Don’t make guesses about the fish’s behavior. Remember, you don’t know this fish yet. Of course, if you see Ich or anchor worms, by all means, start treatment. Give the fish a good 48 hours to settle, explore and get to know the QT tank and then start seriously observing its behavior. Keep and eye out for the usual suspects like Ich, external parasites, the mucous-like stringy feces indicative of internal parasites, etc. Get to know how the fish looks so you don’t have to think back and wonder in 2 months when you spot an odd bump on its side. Get to know its routine and personality. So many fish have died simply because their owners were unable to notice mood changes. Don’t be that fish keeper.

If you do have to treat a fish in QT please remember to set back the 30 day countdown after the problem is remedied. Don’t start and Ich treatment 14 days into the QT and then assume all is well since the last spot fell off on day 23 and the fish has looked fine for days 24-30. Go ahead and set the countdown back to day 0. Don’t forget fish are prone to secondary infections and a host of other illnesses after fighting off one thing. Another full 30 days won’t kill you, but remember; not giving it 30 days sure might kill off a tank of inhabitants if you put a fish in too soon. Not using QT properly is just as bad as not using QT at all. Don’t assume that a week or two is better than nothing.

Once the fish is given a clean bill of health for 30 days, make the transfer to the main tank. If you didn’t treat for anything too terribly, bleach the tank, plants, pots, gravel (if you’re cheap like me and intend to reuse it), airline tubing and sponge or other media, then rinse in water overdosed in dechlorinator. I do this right in the tank. Boiling is also acceptable, but plastic plants can melt, so I prefer bleach and always have it on hand anway. Since you already have a sponge or other media in the main tank (you remembered to put it in like I told you, right?) you can save this old media if you want to go into the tank when you use the currently seeding media. Sometime media is cheap enough to throw away for the extra peace of mind. If you treated something virulent, go ahead and toss it anyway. Better safe than sorry.

So, there you have it. Quarantine tanks are simple, affordable, responsible and dead useful. They save you frustration and hair pulling. They save you money in the long run because they are usually more affordable to treat than a larger tank and they can definitely keep you from having to restock a tank. In that respect, they pay for themselves in no time. They take up little space and can even be stored when not in use. Moreover, a Q-tank is as vital to fish keeping as is water, in my opinion, in that without either, you stand to lose fish. It is my hope that by providing this article to others I can do some small part in helping others avoid the mistakes I have made and enjoy this hobby more fully. Thanks for reading.

Brian Scott Richardson
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