Quarantine or Hospital Tank
Quarantining new fish is a good habit for all although not absolutely necessary. Quarantining is keeping your newly purchased fish in a separate tank enough time to be certain they are disease free. This also allows them to be slowly acclimated to your water conditions. Isolating a diseased fish for treatment is another major reason for having a quarantine tank. For those that keep very expensive fish, a separate tank where fish can be observed and/or treated without the risk of introducing any diseases to the fish in the main tank is inexpensive insurance. Assuring that your newly introduced fish are disease free is one of the best methods of maintaining a healthy aquarium environment. If you are not using a quarantine tank, look for the "Acclimating new fish to your aquarium" article in the basics section of this website.
The major benefits of the quarantine/hospital tank are:

  • Acclimating newly purchased fish to your water conditions.
  • Treating diseased fish.
  • Lower the cost of treating diseased fish since the hospital tank is normally smaller than your main or community tank.
  • Protect otherwise healthy fish from the additional stress of medications in the main tank.
  • Allows use of medications that may have adverse affects on other fish in a community tank.

Setting up the Quarantine/Hospital tank
A quarantine tank can be set up and kept running all of the time or can be setup as needed. Requirements are a heater, thermometer, mechanical filtering and some method of biological filtering to eliminate the toxic ammonia built up through fish waste.

Here are three methods:

1. Set up a separate tank using a heater and a simple sponge filter. Maintain this tank with a few hardy fish such as Zebra Danios or White Cloud Mountain Minnows. The hardy fish will develop and maintain the bio filtration that will cultivate in the sponge filter. This method essentially requires that the tank be setup and running all of the time.
2. If you don't want to have the tank up and running all of the time, you could have an extra filter running in the main tank and transfer this filter to the quarantine tank. When the new fish arrive or a diseased fish requires medication, you can use the water and the extra filter from the established tank. This would give you an instantly established tank ready to use.
3. Still another method that would not require running the quarantine tank all of the time would be to use Zeolites. The Zeolites will absorb the toxic ammonia produced from the fish waste.

Gravel is not required. In fact, I would recommend not using anything for a substrate. This makes cleaning much easier.
Maintaining the Quarantine or Hospital Tank

1. Water changes should be small and frequent to maintain water quality. Daily would be ideal.
2. Clean the sponge filter with chlorine free water at the same temperature as the aquarium. Use the water from your main tank is an excellent way of achieving this. This will keep the bacteria that have formed in the filter alive, eliminating the need to cycle or recycle the tank.
3. Thoroughly clean and disinfect the tank after using for treating sick fish.

If you are introducing new fish, keep them in the quarantine tank for at least two weeks, three weeks would be ideal. Observe them daily for activity and any signs of disease. If diseases do appear, treat accordingly and keep the fish in the quarantine tank an additional two weeks after any signs of the disease have disappeared. A note here. Don't medicate new fish just to be sure, medicating healthy fish weakens them and reduces their resistance to the medications. Only treat them if they are showing signs of disease.