Hospital/Quarantine Tank

What is a Hospital Tank and Why Do I Need One?



A hospital tank is simply an extra tank used to quarantine sick and injured fish. Many experienced hobbyists keep a hospital tank running constantly so it is always available when they need it. You never know when one of your fish may fall ill or become injured, necessitating a move to the hospital tank. If you do not keep a hospital tank set up you could endanger all the fish in your tank by exposing them to the disease for a period of time longer than necessary. In order to protect the health of your fish it is wise to not only learn the basics of setting up and maintaining a hospital tank but to put your newfound knowledge into action.

What is a Hospital Tank?

A hospital tank is simply an extra tank set up to mimic the conditions of your main tank. Most aquarium hobbyists choose hospital tanks that are somewhat smaller than their main tanks, but it is largely a matter of preference. In order to facilitate easy cleaning, it is wise to keep the bottom of your hospital tank bare and to decorate it sparsely. You should still provide your fish with places to hide, but do not use any substrate except perhaps a mesh bag full of gravel from your main tank to introduce a colony of beneficial bacteria. All of the water parameters in the hospital tank should be maintained at similar levels to the main tank to ease the transition for sick and injured fish. Keep your hospital tank as close to the main tank temperature as possible and fill your hospital tank with some water from the main tank to ensure similar pH and water hardness.

Using a Hospital Tank


It is a simple matter to use your hospital tank – all you have to do is transfer the sick or injured fish to the hospital tank and maintain it like you would the main tank. Most aquarium hobbyists recommend installing a sponge filter in a hospital tank instead of a power filter. Sponge filters provide the bare necessities of mechanical and biological filtration but do not produce a current strong enough to endanger sick and injured fish. You should also install a quality aquarium heater in your hospital tank in order to maintain a stable temperature. Even if most of your fish are tolerant of slight changes in temperature, fish that are sick or injured may be more sensitive to these changes and could die in the event of a drastic change.

Once you have your fish settled in the hospital tank you can begin to treat him for whatever disease he has. If the recommended treatment for your fish’s disease is a salt bath, you may choose to dose the entire hospital tank or fill a small bucket with water to mix up the bath. Regardless what option you choose, be sure to research the proper dosage of salt to ensure that you do not cause your fish undue stress. If you are using a power filter in your hospital tank, be sure to remove any activated carbon filter media before starting a treatment regimen. Chemical filters are designed to remove dissolved chemicals and toxins from tank water and they may interfere with the medication you give your fish.

Tips for Hospital Tanks


Keep your fish in the hospital tank for as long as it takes to recover. The recovery period may vary depending on the type of disease your fish has and, unfortunately, some diseases may be fatal. Regardless whether your fish recovers or not, it is a wise move to clean and sterilise your hospital tank after every use. This will prevent bacteria and disease from lingering on tank walls and in the water and it will keep these bacteria from infecting fish you add to the hospital tank in the future. When it comes time to transfer your recovered fish out of the hospital tank and into the main tank, be as gentle as possible to avoid stressing the fish. It is wise to put your fish in a plastic bag filled with some water from the hospital tank and the main tank and to float the bag in the main tank for at least 30 minutes so the fish has time to acclimate. After the 30 minutes is up, carefully net your fish and release it into the main tank.