What is a quarantine tank?
-It is an aquarium set up and maintained apart from your main display tanks. The purpose of this tank is to place new or sick fish to prevent further infestation of your other livestock. The tank is typically somewhere around 5-55gallons depending on the type of fish kept. They normally only have sparse décor and most lack substrate. Filtration is usually just a simple sponge filter or a hang on back power filter as these are easy to seed with media from other tanks and are easy to clean.
Why do I need to quarantine newly purchased fish?
-You may think those newly acquired fish are the picture of health, but what you may not know is they could be a host for internal parasites and bacteria. Symptoms of many aquarium fish diseases do not show signs immediately; the fish can carry the pathogen for quite some time before becoming sick. Your display tank and its livestock may not be as resistant to the pathogens as your new fish, thus you need to make sure your new fish are pathogen free before entering your display tank.
What sort of pathogens can fish carry?
-Any of the common aquarium ailments really. The most common symptomless issues seen in aquarium fish are Internal Parasites and Internal Bacterial Infections. These diseases can go unnoticed by only observing the fish for a brief time before purchasing, especially if the diseases are in the early or more benign stages. Other diseases which can pop up soon after buying fish are external parasites such as Ick, the fish were most likely carrying the parasites to start with but the stress of being captured and moved brought the disease out in full swing.
How to prevent the spread of disease?
-Buying healthy looking fish to start with is imperative, sometimes looks can be deceiving, but buying fish that just look sick is never a good choice. I personally recommend quarantining new fish for a period of at least 2 weeks before thinking about adding the fish to my main tanks. This period of time allows you to observe the fish more closely and do some preventative treatment against any dormant pathogens before adding the fish to your display tank. If you notice any symptoms or disease during this time the issue is much easier to treat and isolate in a separate quarantine tank than inside your display tank. It is also a good idea to never share equipment between your quarantine tank and your display tank.
What equipment will I need for a quarantine tank?
-This can be as simple or elaborate as you like. Here are my personal recommendations:
*Aquarium, any size appropriate for the fish you are isolating
*Hang on back filter, these are easiest to use as you can easily seed with media from one of your established tanks
*Reliable heater appropriate for the aquarium (if keeping warm water fish)
*Easy to clean décor (ceramic pots, PVC pipe, plastic plants, etc) anything that can withstand a good bleaching and is aquarium safe will do the job
*Do not use substrate, many bacteria and parasites can live within the substrate bed thus it is best to keep the tank bare bottom, it also allows for easier cleaning. You can instead paint the bottom and back of the tank to enhance the tank’s appearance and reduce fish stress
*Lighting source, this doesn’t need to be fancy…any safely applied lighting fixture will work
*Cleaning/Maintenance equipment (net, siphon, bucket, algae scraper, etc) these items are to be used on the quarantine tank only. It is possible for pathogens to be spread via shared aquarium equipment. Not sharing equipment keeps any possible disease isolated.
Do I need to cycle the quarantine tank?
-No, you don’t even need to keep the tank running unless you have fish in it. You can simply set the tank up if you need it such as with buying new fish or treating a sick fish. You can place some used media from one of your other tanks in the quarantine tank’s filter and it is pretty much instantly cycled. You will need to keep a close eye on water parameters and do more frequent water changes than you would on a display tank (2-3X per week) to remove any excess waste your added bacteria cannot handle. It is actually a good idea to tear down the quarantine tank when it is not longer needed and give it a thorough cleaning with a 10% bleach solution to kill out any possible pathogens.
How long to quarantine new fish?
-2 weeks minimum, more time is naturally better. If everything checks out within 14 days the fish are probably ok to add to your display. If the new fish have been sick, wait for at least 2 weeks after you have determined the fish have recovered from their ailment before adding them to the display.
Do fish in quarantine need special treatment?
-Yes, you should do preventative treatment against common internal parasites while the fish are in quarantine. You should also feed the fish a very high quality diet to improve their overall health and aide in disease resistance before moving them to your display. Feeding them a varied diet including a quality base processed fish food in addition to various frozen or freeze dried foods will do the trick. Soaking some of their food in food soaks will also improve overall health. Garlic extract has been shown to help ward off parasites while extra vitamin C can prevent some cases of HITH disease. I use a food soak at least 2-3 feedings per week and alternate between Garlic extract and Selcon.
What medications should I use on the fish in quarantine?
-Many of us use a combination of Prazi-Pro and Metro as a preventative against internal parasites on fish which appear to be in good health. The reason behind that is internal parasites are very common in domesticated fish and often go overlooked, they are also easily spread to other fish. Here is my recommended usage of Prazi-Pro and Metro:
*1st Day-add new fish and seeded filter cartridge. Dose Prazi at full strength and Metro at 1/2 strengthAfter 48-72hours following this treatment regimen I contemplate adding the fish to the display. If there are no symptoms it is generally safe to add the fish.
*3rd-4th Day-50% WC 1/4 dose of Prazi, 1/4 Dose of Metro
*7th Day-50% WC...no new medications
*10th Day-50%WC...no new medications
*12-13th Day-50%WC...no new medications, add carbon to suck up any trace meds
What if my fish come down with a disease in quarantine?-Identify and treat the disease. There are a ton of great medications out there and lots of informed people to help you nail down the specific issue. Aren’t you glad this happened in quarantine instead of in your display tank?
What if I have a sick fish in my display?
-Follow the guidelines for quarantining a newly purchased fish, and treat the disease. Again once the fish appears to have recovered from its illness wait 2 weeks before adding the fish back to the tank. Watching your fish on a day to day basis will help you to notice slight changes in behavior or appearance before an ailment gets out of hand. The quicker you take action the more likely you will be to stop an outbreak from wiping out your whole display.
Do I need to use the Prazi/Metro treatment for the sick fish I recently added from my display?
-Not unless you have determined that the fish has a disease which would benefit from treatment with these two medications. Treat only the disease your fish appears to have and give it an ample observation period to watch for secondary infections before returning it to the display tank.