When you buy new fish to add to your existing aquarium, you really should quarantine the new fish in order to check them out. To add them in directly might contaminate your existing tank and/or make your new fish sick. You would then need to treat all your fish, new and old, to medical treatment and risk the possible loss of existing fish.
I added some new goldfish to our existing tank straight from the fish store and one had ick, which then infected the rest of the fish. With sea salt (3 tsp/gallon, 0.3% concentration), increased water temperature and a month of time, the ick was defeated. This ick treatment weakened my existing fish and stressed both of us out. Far better to enjoy your display tank for a month while the newcomers get to reduce their stress in the quiet of a quarantine tank (QT).
My quarantine tank is a 10G, bare bottom tank with 2 plastic plants, located in the basement. Spartan it is, and I feed the fish every other day. I have two Aquaclear filters, a 30 and a 20, for a total of 50, overkill for filtration, but these a Aquaclears allow me to stock it full of biomedia. The tank is cycled. I also add 0.1%, 1 tsp/gallon sea salt as a preventative measure and also to thicken their slime coat. I have an LED light on a timer so they get light about 8 hrs/day. This is a simple setup.
There is a cost associated with a QT. There is the 10G tank, a cycled filter, space required and a light. You do need to test water parameters and change water accordingly, though this should be much less than your main tank because there should be less fish in the QT than your main tank. It still requires more work. These costs, however, are minimal. Once you finish with the QT, simply pack it away. Put the biomedia into your main tank so it remains cycled.
Consensus from a lot of aquaria web sites say that quarantine should be a month after you see no signs of sickness. Sure I would like to simply add the newbies to my main tank, but the risks are high. New fish are stressed from the long trip to the fish store and then stressed again to your house. This makes them susceptible to diseases that a healthy fish would be able to easily fight.
Of course you need not take anyone’s advice. At least know the risks you take. My little ick scare was enough for me. I QT all new fish for at least a month.
Helpful Links:
–A Fish Quarantine Process
–An Ounce of Prevention is Worth a Pound of Cure: A Quarantine Tank for Everyone
–Quantine Procedures for Goldfish, 2
–Rain Garden Quarantine Procedures
