opinions on Quarantine Tanks

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saiwong

Aquarium Advice Regular
Joined
Jul 25, 2022
Messages
64
Hello,

Just want to know everyone's opinion on use of Quarantine tanks.
There seems to be alot of different opinions (even from the YouTube experts)

Many never use them because they think they add another element of stress to the fish, adding to the list of stresses the fish have had to endure to arrive into your home aquarium.

Also seem different opinions on use of medication. Some people always use medication to stop the spread of diseases like Ich from infecting other fish, whilst others feel medicating fish that have no indication of disease would just add another level of stress to the fish. Also if they medicate, this differs from
1 week, 2 weeks, 3 weeks up to 4+ weeks.

so what is your practice

(a) never quarantine
(b) quarantine but don't medicate unless you start seeing signs of disease
(c) quarantine and immediately medicate just to be safe

also if you quarantine, for how long (1, 2 ,3 , 4+ weeks) ?
 
In my opinion, most YouTube "experts" are not that smart and don't know what they are talking about. Some do but a lot don't.

All zoos, public aquariums, and smart farmers will quarantine new livestock to reduce the chance of introducing diseases to their current stock. A lot of dog & cat breeders do it and so do some bird breeders. Home aquarists should do the same.

Quarantine tanks should be used for any new fish, shrimp, snails and plants (if the plants come from tanks containing fish). If you don't use a quarantine tank, you risk introducing diseases to the established display aquarium and potentially killing everything you already have in the main tank. You also risk introducing parasites like intestinal worms and gill flukes, which don't always show themselves or produce any symptoms for months after. By which times it's too late and all the fish are infected.

Not using a quarantine tank is a bit like adding chlorinated tap water to an aquarium and adding the dechlorinator to the tank at the same time. You might get away with it for a while, but one day it will go bad.

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A properly set up quarantine tank will not stress new fish. It should have a thin layer of substrate, some plants (real or fake) or caves, an established biological filter, heater if required, a coverglass, and be a nice home for the new fish.

The new fish should be quarantined for at least 2 (preferably 4) weeks. If they get a disease, the quarantine period (2-4 weeks) starts again after the fish have recovered from their ailment.

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All chemicals added to an aquarium will stress fish to some degree. Because of this, the only medications that should be used prophylactically are deworming medications like Flubendazole, Levamisole & Praziquantel. Deworming medications are much less stressful than most other medications, and using them on new fish in quarantine means you don't have to treat multiple tanks or bigger tanks should the new fish introduce worms into the main display tank/s.

Most aquarium fishes from fish farms are infested with intestinal worms like Camallanus and or tapeworm. Sometimes the fish show symptoms, other times they don't. However, the worms do spread in aquariums and once they are in one tank, they are in all your tanks. So deworming fish while they are in quarantine, is a good idea.

If other fish diseases appear on the fish while they are in quarantine, they should be treated for those specific diseases. But that is it. If they don't get any diseases, they don't get medicated (besides deworming).

Using medications on any organism that doesn't have a disease, simply increases the risk of drug resistant pathogens developing in or on the livestock, or in its environment. This is already the case for many fish medications. Things that used to work 40 years ago, no longer do anything to control disease organisms. We also have issues with drug resistant bacteria in hospitals and on poultry products coming out of commercial abattoirs. This is caused by mis-using medications. People use the wrong type of medication. They use medications when they aren't needed. They don't use the medication correctly.

Most fish health issues are caused by poor water quality. And lots of fish diseases can be treated with salt, which is a lot safer than chemical based medications that often contain preservatives and carcinogenic substances like Formaldehyde and Malachite Green.

White spot and velvet can be treated with heat (30C/ 86F) for 2-4 weeks.

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Using Salt to Treat Fish Health Issues.
For some fish diseases you can use salt (sodium chloride) to treat the ailment rather than using a chemical based medication. Salt is relatively safe and is regularly used in the aquaculture industry to treat food fish for diseases. Salt has been successfully used to treat minor fungal and bacterial infections, as well as a number of external protozoan infections. Salt alone will not treat whitespot (Ichthyophthirius) or Velvet (Oodinium) but will treat most other types of external protozoan infections in freshwater fishes. Salt can treat early stages of hole in the head disease caused by Hexamita but it needs to be done in conjunction with cleaning up the tank. Salt can also be used to treat anchor worm (Lernaea), fish lice (Argulus), gill flukes (Dactylogyrus), skin flukes (Gyrodactylus), Epistylis, Microsporidian and Spironucleus infections.
 
While i support Colins opinion on quarantining and always recommend quarantining new fish, your question was what do people actually do.

Im less risk averse with my own fish than with other peoples and i dont quarantine new fish. I only quarantine sick fish and i dont buy sick looking fish. I trust where i buy my fish from and ive never had an issue with any livestock ive bought.

Don't do as I do.
 
I'll toss my hat into this ring. ;)
The reason you quarantine new fish is because A) you don't know what diseases they have been in contact with. B) you want to make sure the new fish are healthy and strong enough to handle themselves in your main tank. C) after medical treatment or injury /disease recovery you want the fish to get to a stronger state before returning to the main tank. D) You don't want to bring in any unknown/unseen pathogens into your main tank.

IMO, you use a "Hospital tank" for treating fish diseases or injuries. What's the difference in the tanks you ask? A quarantine tank should be a less elaborate setup that mimics your main tank so that the fish can get used to your feeding schedule, lighting schedule, water change schedule and foods you feed all without the stress of having to compete with existing fish. A Hospital tank is more a bare bottom tank with simple filtration or just an air stone depending on what kind of medication you are using. In most cases, the medicines used have water changes included into the treatment so a " cycled" tank is not necessary for treating the fish. Because this kind of setup is temporary, it does not need to be up and running constantly, can be set up and used quickly and is usually a 10 gal tank for most smaller fish or a tank large enough to handle larger fish but in an increment of the medicine to be used. In many cases, the medicines are pre packaged for 10 gallons of water so if you measure out 5 gallons of actually water into the tank, you can split the dose in half and still be using it at full strength. Just a hint, a 10 gallon tank does not hold 10 gallons of water, even empty, so if you want to properly use the 10 gal dosage, you use a 15 gallon tank with only 10 measured gallons of water in it.

As for the medications themselves, there is no "One shot cure all" medicine so it's best to use the medications that are designed to treat the specific ailment your fish has. If you don't know what the fish has, I suggest getting a good book on fish diseases to help you diagnose the problem. ( The internet is not a good source of info for this.)For the same reason you don't go to a foot doctor to treat your high blood pressure, you don't add medicines that won't work on your disease/condition. There are a few good books on diseases with pictures of the diseases to better help you identify the issue. If you can get one that also has a diagnostic flow chart, that's even better. The ones I use are a " If this than do this, if that then do that" kind of flow chart.

As for how long to medicate all depends on the medicines being used. Some have a 1 day or 3 day or 10 day treatment. Some have longer treatments. It all depends on what you are treating. Antibacterials work differently than antifungals and antiparasitics work differently than the others. Then there are the antivirals. :blink: You end up with a medical degree when you keep fish as a hobby. ;) :lol:

As for length of time to quarantine: I'll say this, there are parasites that have a life cycle of 120+ days so any quarantining less than that can leave yourself open to infestations in your main tank(s). Bacterial issues generally start happening within a few days of arrival. Fungal issues can start about a week after an injury. Ich can happen usually within a few days but does not usually get the aquarists attention until it's a full blown case and spreading.

There is something else to consider: mixing wild caught fish with farmed fish usually ends up with a bad result because farmed fish tend to have mutated pathogens that differ from wild ones. In many cases, the farmed fish are raised in medicated water, shipped in medicated water, then medicated again when they get to the wholesaler and/or seller. The need to preemptively medicate is no longer a good idea. Treat only what needs to be treated. In the case of deworming, it's a good idea for most farmed fish. With wild caught fish, many places now have medications that they treat the fish with when they are first collected and housed before going to the shippers so again, preemptively medicating wild caught fish is not necessary. Treat any disease that arises. That said, many ground dwelling wild caught fish, including Cichlids, Gobies, Catfish, Geophagus, etc should be dewormed unless you know that the fish have already been dewormed after capture. There is a greater chance that they have worms than they don't. :(

Hope this helps. (y)
 
If you’re lucky enough to have a local store, that will eliminate many problems. My local store has been in business 50 years. They know when to quarantine. And I know which days they receive shipments and I wait five days past that for purchase. If you only have box stores for purchase, it’s a crap shoot.
 
Thanks for all the opinions, they are greatly appreciated.

I used to quarantine new fish for 2 weeks (only medicating when I see signs of illness).
However, will now increase quarantine time to 4 weeks since last time I believe my fish
showed signs of Ich during the 3rd week of getting them from the local fish store (LFS).

Also I will also start quarantining plants as well. I didn't know disease (like Ich) could drop off a fish and rest of surface of plants before hatching. Always good to grown knowledge on how to better care for your fish.
 
However, will now increase quarantine time to 4 weeks since last time I believe my fish
showed signs of Ich during the 3rd week of getting them from the local fish store (LFS).

This ties in with the lifecycle of the ich parasite. At tropical water temperatures the lifecycle is 2 to 3 weeks. You buy an infected fish that shows no signs of infections, 2 to 3 weeks later once the parasite has gone through a complete lifecycle the fish is reinfected.
 
Colin, Aiken, and Andy may recognize me from a separate thread where I bemoan the loss of 75% of my tank (and counting) to what I can only attribute to the recent addition of 5 store bought fish.

I'm at a loss here. I get the need to quarantine new fish, but practically, it's kind of a non-starter. Even if only a ten gallon, and even with only a hanging filter, that takes up a not-insignificant amount of space, and requires maintaining an active media culture in a tank I will only use for the 4 times a year I might add new fish. I get that the trade-off is running the risk of what just happened to my tank, but I have a hard time believing that most amateurs like myself, and I've been at it for close to 10 years, are set up to maintain a quarantine tank that will sit largely unused most of the time. I have a hard enough time justifying to my wife my ever growing aquarium budget without adding an entirely new tank that will sit mostly unused.

I'd be very interested in the opinions of others on this. Believe me, I just lost 2 dozen fish in a 36 hour period to an as yet unidentified problem. I'm leaning towards having a QT but the impracticality/challenging logistics of maintaining one is a high bar.
 
Colin, Aiken, and Andy may recognize me from a separate thread where I bemoan the loss of 75% of my tank (and counting) to what I can only attribute to the recent addition of 5 store bought fish.

I'm at a loss here. I get the need to quarantine new fish, but practically, it's kind of a non-starter. Even if only a ten gallon, and even with only a hanging filter, that takes up a not-insignificant amount of space, and requires maintaining an active media culture in a tank I will only use for the 4 times a year I might add new fish. I get that the trade-off is running the risk of what just happened to my tank, but I have a hard time believing that most amateurs like myself, and I've been at it for close to 10 years, are set up to maintain a quarantine tank that will sit largely unused most of the time. I have a hard enough time justifying to my wife my ever growing aquarium budget without adding an entirely new tank that will sit mostly unused.

I'd be very interested in the opinions of others on this. Believe me, I just lost 2 dozen fish in a 36 hour period to an as yet unidentified problem. I'm leaning towards having a QT but the impracticality/challenging logistics of maintaining one is a high bar.

In the 50+ years of keeping fish, I've seen a lot of changes in the fish themselves as well as the methods used in breeding them commercially as well as where they are being collected as well as diseases that have entered the hobby. As one of my buddies who is also in the fish business for over 40 years says to me, " it ain't like the old days. " :(

Today, more so today than 40- 50 years ago, there are more commercial breeding farms around the world so more farm raised fish are on the market than wild caught specimens so we need to think about them as two distinct and separate beings. Wild fish will not have the pathogens that farm raised fish will have or have the resistance to the pathogens a farmed fish has. The same goes in the opposite direction, farm raised to wild. With that, the medicine that will cure a natural pathogen may not cure a similar pathogen from a farm produced fish. So keeping that in mind, it's actually best not to mix farmed fish and wild caught fish in the same tank. That means the hobbyist needs to be more aware of the origins of the fish they are purchasing or receiving.

As to the question at hand, a quarantine tank need not be a large endeavor if you are only bringing in smaller fish in smaller quantities. It also does not need to be in operation full time if you keep a "spare" filter media in your existing tank so that when you know you are purchasing new fish, you set up the quarantine tank, add the spare media into a filter for the quarantine tank, and if the water in the main tank is healthy, transferring some of that into the quarantine tank and then add the new fish. The nitrifying bacteria reproduce rather quickly so any ammonia rise should be handled before any harm is done or the use of items such as Seachem's PRIME, which detoxifies the ammonia, can be used if the Ph of your water is higher than 7.0. ( ammonia in water under 7.0 is naturally converted to the less toxic ammonium so no need to use anything. )

The ultimate decision is of course yours but you have this to consider: If you have a nice running tank and you don't want to risk losing your stock, don't add any new fish. Another option is to take your chances and hope for the best because you may not be able to save your stock should you add a pathogen to your tank that does it's damage before you notice. Another option is to maintain species only tanks where you obtain all your fish
for the tank at one time and so the tank now becomes the quarantine tank as well as the main tank once the quarantine period is over. That takes a conscientious effort on the part of the hobbyist to not indulge in "unplanned purchases."
In every fish group I've been on online, I've read posts that follow this path: My tank has been running for a long time and I added some new fish and they wiped out my tank. I never quarantined fish in the past so I didn't do that now. On one site in particular, there was even a person who said he was in the fish business 30 years ago and never quarantined the fish and never had anything like this happen to him.....EVER!!!. He lost some marine fish he had had for over 10 years all because he didn't keep up with the current diseases being brought in on new fish. It happens all the time. :(

So my opinion holds that there is no upside to not quarantining today's fish.

Hope this helps. (y)
 
Colin, Aiken, and Andy may recognize me from a separate thread where I bemoan the loss of 75% of my tank (and counting) to what I can only attribute to the recent addition of 5 store bought fish.

I'm at a loss here. I get the need to quarantine new fish, but practically, it's kind of a non-starter. Even if only a ten gallon, and even with only a hanging filter, that takes up a not-insignificant amount of space, and requires maintaining an active media culture in a tank I will only use for the 4 times a year I might add new fish. I get that the trade-off is running the risk of what just happened to my tank, but I have a hard time believing that most amateurs like myself, and I've been at it for close to 10 years, are set up to maintain a quarantine tank that will sit largely unused most of the time. I have a hard enough time justifying to my wife my ever growing aquarium budget without adding an entirely new tank that will sit mostly unused.

I'd be very interested in the opinions of others on this. Believe me, I just lost 2 dozen fish in a 36 hour period to an as yet unidentified problem. I'm leaning towards having a QT but the impracticality/challenging logistics of maintaining one is a high bar.
One of your points is that most hobbyists don't have a quarantine facility. This i agree with. Forum members wont be a representative sample of the hobby. The vast majority of hobbyists will have a small to medium sized tank, with commonly kept community fish, probably overstocked. Little knowledge about whats going on in their tanks with regards to water chemistry and they arent doing a great deal of water maintenance. For the most part they will get by and muddle through because things usually just tend to work. When their fish get sick they will likely die, when their fish die they will go to the fish store once or twice a year to replace them. They dont quarantine these fish and most of the time they get away with it.

They will only start to look into whats going on and what more knowledgable people consider to be good practice when something goes wrong. Their first port of call will be their fish store and maybe social media. When that doesnt deliver the expected results they will come here. And after a while, either their issue is fixed or they just go back to muddling through, we don't hear from them again.

Its risk/ reward. Only you can decide how risk averse to be. You have seen the extreme side of what can go wrong if you dont quarantine new fish. Is it worth the risk to you of similar happening again sometime in the future?
 
No, it's not worth the risk to me. I'm never going to get emotional about fish -- they're not dogs. But I was very fond of the tank I'd built over the past 5 years of tinkering. I wouldn't say I was a muddle-through kind of hobbyist. I've been at it for more than 10 years, but got more serious 5 years ago and worked on building a good tank. Yeah, mostly tetras, but tetras are a diverse group and black skirts are hardy as hell. They're the only survivors in my tank, along with my bristle-nose pleco. But my school of rummy-nosed tetras made the tank. I've had them (15) for more than 2 years, and built the tank-mates around them. Great plants. CO2, a high tech light, great piece of driftwood. People were surprised to see this side of me. Watching helplessly as more than 2 dozen fish died over 3 days is an experience I'm in no hurry to repeat. I'll repopulate the tank but I'm trying to figure out how to go about running a QT without driving myself nuts.

I appreciate the time you, Colin and Andy took to walk me through this mess. This is a great forum
 
No, it's not worth the risk to me. I'm never going to get emotional about fish -- they're not dogs. But I was very fond of the tank I'd built over the past 5 years of tinkering. I wouldn't say I was a muddle-through kind of hobbyist. I've been at it for more than 10 years, but got more serious 5 years ago and worked on building a good tank. Yeah, mostly tetras, but tetras are a diverse group and black skirts are hardy as hell. They're the only survivors in my tank, along with my bristle-nose pleco. But my school of rummy-nosed tetras made the tank. I've had them (15) for more than 2 years, and built the tank-mates around them. Great plants. CO2, a high tech light, great piece of driftwood. People were surprised to see this side of me. Watching helplessly as more than 2 dozen fish died over 3 days is an experience I'm in no hurry to repeat. I'll repopulate the tank but I'm trying to figure out how to go about running a QT without driving myself nuts.



I appreciate the time you, Colin and Andy took to walk me through this mess. This is a great forum


No disrespect to anyone hear but this is the kind of mindset that occurs naturally in all walks of life and I personally don’t find it helpful.

For example, someone is ‘getting by’ because they are using practices that don’t fall in line with the masses of a particular group, this is automatically construed as that are muddling through and have largely been successful by accident? (think about what I’m saying before anyone thinks about reacting defensively please) I know there was no malice behind the comment but this reinforces my stance on confirmation bias that really does need to be undone if we are going to progress. So Jcmcn5 I could understand if you were offended by the comment.

Quarantine tanks have pros and cons and there usage needs to be weighed up. This is not a black and white world. The biggest pro is that you MAY have a higher chance of preventing a tank wipe out when introducing new fish. Thats a great advantage but when you consider the negatives like you say cost, space, upkeep then you are looking at doing a risk assessment and deciding whether or not in is worth it to you to add new fish straight to the tank. If you decide it is worth the risk then we can look at other ways to minimise thats risk. Those things would be, knowing your supplier and how they configure their tanks, staking out the store and checking the condition of the tanks and the fish they have. Introducing them correctly, mixing them with the right species, checking the TDS of the store water vs your own (this is important).

If you can do this assessment and decide that the risk is still worth taking then kudos to you and don’t feel ashamed that you don’t have a QT. We didn’t even ascertain if that was the true cause of the deaths in your thread after all. Just restock and go again.
 
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I took no offense from any of the comments. I asked for the input, and they were kind enough to give me both sides of the argument. They also made it clear what the trade-offs are, and that ultimately, it's my call. I may very well do as you suggest and just repopulate with a QT but getting both sides of the issue from a site like this is all part of the data input that will inform my decision. I appreciate the points of view I get from anyone who takes the time to respond. I have a pretty thick skin.
 
I would appreciate hearing more about total dissolved solids. I confess it's a term I'm not familiar with (perhaps further highlighting my ignorance). How would I go about comparing the water from my LFS with my own?
 
I would appreciate hearing more about total dissolved solids. I confess it's a term I'm not familiar with (perhaps further highlighting my ignorance). How would I go about comparing the water from my LFS with my own?


I did a write up on it in 2014.

https://www.aquariumadvice.com/forums/f12/importance-of-tds-319174.html

Many other sources online too.

Sorry not sure how to link within the app.

You need a conductivity meter. They are searchable by the term TDS meter online. They are cheap as chips and pretty much the most accurate dip test we have.

My tap water has a TDS of about 46ppm. My tank currently 150ppm. I used to fail miserably with fish from two specific reputable stores. Healthy looking fish and clean tanks. An abundance of advisors and hand etc. Both had water in the bags the fish came in measuring a TDS of 800ppm+

My not so nice ‘mom and pop’ store around the corner that at best neglected their tanks with fish never looking in the best condition always seemed to have the best results i.e I never lost a fish from this store. Their water measure 50ppm same as my tap. Unfortunately, their RO water was also the same as our tap which suggested they didn’t even bother changing the membranes or the RO system was just hooked up to the tap. Still sold as RO though.

Sometimes the ‘best stores’ have the worst water. But also those potions they squirt in to the bags are often full of sodium and or chloride ions. Those two ions in particular can wreak havoc on fish if exceed other ions that compete for uptake.
 
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That thread was written so long ago and after re reading I can acknowledge it’s not the greatest.

In a nutshell. The fish are constantly trying to regulate ion loss and uptake.

Osmosis is an act of balancing. Like everything else on earth. In order to try and achieve a balance water will always moves in the direction of a higher solute (salt in our example) concentration. It wants to dilute the salts to try balance both sides of a semi permeable membrane. The semi permeable membrane being the fishes skin/scales. In fresh water. The fish are always saltier than the surrounding water so the water wants to go in to the fish. The fish will urinate to release this water and lose valuable ions in the process and so ions with diffuse through the gills of the fish to maintain balance. The fish are doing this constantly but will achieve a semi balance known as the osmotic pressure

Osmotic pressure is the hydrostatic pressure produced by a difference in
concentration between solutions on the two sides of a surface such as a semi permeable membrane or cell.

fish must keep on osmoregulating ... spending much energy retaining salts and excreting water. If you change the osmotic pressure the fish will need to. Adapt. The fish have no say in this however, this is mostly a passive function control by ionic charges. It requires a lot of energy.

Fish that are subject to large and or continuous TDS fluctuations can become stressed. When fish become stress cortisol is released and damages the gills by altering the cellular structure. This is one of the main reasons I like to keep TDS stable and I’ve had unparalleled success ever since.
 
TDS stands for total dissolved solids.

If we were to evaporate all the water from a solution. You would see all the salt crystals of varying compounds. You weigh those crystals and that gives you the TDS value.

Unfortunately, in an aquarium this is not practical. What we need to do is measure the conductivity of the water using a meter. This is because many particles in the water are ions and ions either have a positive or negative charge. The conductivity meter can measure these. Sugar however has no charge. However, if we were to evaporate the water it would still count towards the total weight and TDS. So conductivity though close to a true TDS is not truly accurate. The conductivity meters uses a known factor that extrapolates the conductivity which is measured in micro siemens in to a TDS value measured in parts per million and we use this value.

Rain water will have a TDS close to zero though can be much higher depending on where you live. I know someone who’s rainwater has a higher tds than my tap. This is due to the geology in the area and carbonate dust in the air collecting in the rain and on roof tops etc.

So although TDS won’t tell you what the ions are you can use them to spot trends. If you allow water to evaporate for example and top up with tap only you will be increasing the TDS over time. At some point the TDS could be quite high and then you do a large water change and the fish react.

If you have ever had crypt melt then this is 99% the cause. Plants also use osmosis. They are used to functioning at a certain osmotic pressure but the sudden change is too much to regulate and so their leaves melt.
 
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Are hospital/quarantine tanks necessary? No…. But can it help alleviate stress on your main tank and the cost of medicating the entire main tank? Yes

I’ll admit, I’ve also just tossed new fish into my main tank, but I also didn’t have an extra tank at the time so we take our chances and live with that decision however it turns out. 99 out of 100 times it’s fine or at the most a minor inconvenience if there’s an ailment to treat, but there’s also that 1 time where that decision could be the end of your main tank!

I’ve now got a dedicated tank for hospital/quarantine, it really doesn’t cost much for a small tank and when not needed for its intended purpose it is home to my blue velvet shrimp (low maintenance and cheap!). If you don’t want to keep another tank running, just keep a piece of filter media (sponge) cycled in your main tank so you can easily and quickly fill up your hospital/quarantine tank, drop in your cycled media and you’re good to go
 
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