How to Quarantine Fish the Easy Way
A quarantine tank is one of the best ways to prevent your fish from becoming sick. This separate aquarium is used to temporarily hold newly purchased fish or ailing animals that need a quiet environment to heal. You can monitor their health, give them treatments and prevent illness from spreading by keeping them isolated. Once they are fully healthy and free from disease, you can safely add them into your main aquarium without infecting any existing fish.
Materials for the Hospital Tank
– Clear plastic tub or aquarium with a lid – Aquarium filter with low flow, like a sponge filter – Aquarium heater and thermometer Aquarium decorations and hides Water conditioner – Trio of quarantine medications (includes Mardel Maracyn, Aquarium Solutions Ich-X, and Fritz ParaCleanse)
How to Set Up a Quarantine Fish Tank
1. To avoid cross contamination, place the quarantine tank in a different room away from your main display tanks if possible. You can also use separate nets and siphons to quarantine your fish tank and wash your hands after handling it. 2. If you are using a plastic tub, prepare the lid by drilling some holes for air flow and cutting a small rectangle on the side for power cables and airline tubing to pass through. Another optional step is to mark up the side of the tub with 1-gallon measurement lines to help make water changes and medicine dosing easier.
As a cheap way to quarantine, a clear plastic container is an option. Drill or cut holes in your lid for easier equipment installation and better air flow.
1. Add water conditioner to the hospital tank. 2. Install the aquarium filter and heater, and add fish tank ornaments to give the animals some shelter. You don’t need gravel or any other substrate as a bare-bottom setup makes it easy to clean the tank and inspect the fish wastes if necessary.
Use a bare bottom tank with aquarium decorations to provide plenty of cover. The extra shelters will help sick fish hide better.
1. Add the fish, observe their physical appearance and behavior, and treat with medication if needed. Remove all chemical filtration (such as activated carbon and UV sterilizers) before adding any medicines. 1. If you know the cause of the illness, then treat your fish immediately. Follow the instructions on the package. You can find out what disease your fish are suffering from by reading this article. 2. If you purchased fish from a local fish store or breeder that you trust to have healthy animals, feed and observe the fish for a couple days. You can see Step 5a above to identify an illness. ParaCleanse may be recommended to prevent you from becoming ill. 3. If you bought new fish from an online retailer, pet store chain, or untested source, proactively treat them with the quarantine medication trio. These medicines contain a blend of antibiotic, antifungal, and anti-parasitic active ingredients that are safe for scaleless fish, fry, shrimp, snails, live plants, and beneficial bacteria. For every 10 gallons, take 1 packet each of ParaCleanse and Maracyn. 1 packet of Ich-X (5 ml) is also recommended. The medication should be left in the water for 7 – 10 days.
Description of quarantine medication trio
1. Regular water changes should be done every week once the treatment is complete. This will allow you to slowly remove the medication over time. Help the fish to build up their immune systems by feeding high quality fish food like frozen foods, which are nutritionally dense and easy to clean up. 2. We recommend keeping all new fish in quarantine for at most 4 to 6 weeks from the time of last illness or death. You can also add two healthy fish to your main aquarium to the fish hospital tank, and then see if any of them get sick. If everyone is healthy, you can release the quarantined fish. 3. After quarantine is completed, you can clean and dry the hospital tank. If you plan on purchasing more fish in the near future, just leave everything running so that it will be ready for the next batch.
Most Common Questions about Fish Quarantine
What size quarantine tanks should be?
Because it is temporary, the quarantine tank doesn’t need to be larger than the recommended size for permanent housing. You can also use less medication to treat the fish in a hospital tank that has a smaller water volume.
How do you keep a quarantine tank cycled? The easiest way is to run a spare sponge filter (or extra filter media in a hang-on-back filter) in one of your display aquariums. Whenever you need to quarantine some fish, move that extra sponge filter or filter media to the hospital tank so it will bring over lots of beneficial bacteria to help purify the water. After the quarantine period ends, return the sponge filter or filter medium to your main tank. To find out what is cycling and how to cycle an aquarium, see our full article here.
Run an extra sponge filter or filter media in an established tank, and then use it to bring beneficial bacteria to the hospital tank when needed.
Can I quarantine fish inside a bucket? Yes. Any clean, food-safe container large enough can be used in an emergency. We recommend that you use a container with clear sides to allow you to view the fish from all angles and see if they are improving or getting worse.
Should you quarantine shrimp and snails? Dwarf shrimp can sometimes carry diseases, especially if purchased directly from importers, so if you are bringing in a batch to add to an existing colony, consider putting them in quarantine first to observe their condition. In our experience, snails rarely seem to carry illnesses, so we usually skip the quarantine step and add them directly to our aquariums.
Do I have to quarantine my first fish? If you are setting up your first tank, you can theoretically add new fish directly into the aquarium without setting up a separate quarantine tank since there are no existing animals to protect. One situation where you might want to use a separate hospital fish tank is if your aquarium is very large and the fish are small enough to go in a scaled-down quarantine setup. It will cost less money to dose medication in a smaller volume of water rather than an entire display tank.
Another instance would be if your main aquarium is full of live plants or snails. In cases where the quarantine med trio does not seem to be effective, we often turn to aquarium salt as a second line of defense. Snails and plants don’t like high salt concentrations so it is best to move your fish into another container.
What should I use to treat fish if I can’t buy the quarantine med trio? We recommend using aquarium salt – a cheap and widely available “medicine” that is quite effective for broad-spectrum treatment of bacteria, fungus, and external parasites. However, it is not safe for aquatic plants, snails, and certain fish like anchor catfish. For more information, follow the dosage instructions in our aquarium salt article.