Quarantine and Hospital Tank Setup: Protecting Your Aquarium

A simple quarantine tank is the single best way to keep new fish from introducing disease to your aquarium. Learn why quarantine matters, how long to quarantine, how to set up a basic hospital tank, and the biosecurity habits that make it work.

Why quarantine

Quarantine means isolating new or sick fish to prevent introducing or spreading infectious disease - a standard, important practice in aquaculture and the home aquarium. A quarantine period lets you observe new arrivals, treat problems before they reach your main tank, and reduce the chance of an outbreak among established fish.

How long

Merck gives a minimum quarantine of 30 days, with longer periods often necessary; university guidance commonly recommends 30 to 90 days for new fish. Some diseases require specific conditions - for example, koi are held at least 30 days at around 24 C (75 F) to guard against koi herpesvirus. For marine ich (Cryptocaryon), UF/IFAS advises a minimum of three to six weeks at 24-27 C.

A basic hospital or quarantine tank

• An inexpensive small tank (around 10 gallons), a sponge filter, an air pump for aeration, and a heater.
• Keep it bare and simple; avoid substrate and porous rock that can bind medications such as copper, and remove activated carbon while medicating (it strips out the drug).
• No invertebrates in a tank being treated with copper - they will not survive it.
• Dedicated equipment - nets, buckets and siphons used only for the quarantine tank.

Monitoring

Watch quarantined fish closely for parasites, breathing problems and appetite changes, and test water quality regularly in the small volume. Examine any moribund fish and, where possible, have dead fish examined to identify what you are dealing with before it can spread.

Sources: Merck Veterinary Manual, Management of Aquarium Fish (www.merckvetmanual.com); UF/IFAS FA164, Cryptocaryon irritans (ask.ifas.ufl.edu); UF/IFAS FA165, Use of Copper in Marine Aquaculture and Aquarium Systems (ask.ifas.ufl.edu); UF/IFAS FA101, Quarantine of Fish (edis.ifas.ufl.edu).