Tropical fish are susceptible to an abrupt change in water temperature, and their condition is directly affected by overcrowding. To transport tropical fish by car, it is best to remove them from the aquarium unless it is a small one of five gallons or less that can be moved without too much danger of breakage.
It probably will not be necessary to feed the fish. Many species can go without food for as long as a week with no ill effects.
An unbreakable container of a size easily handled when it is half-full of water (minnow bucket, ridded container with air holes in the lid) makes a convenient carrier. Or, use a leak-proof plastic bag closed with a rubber band, place it in an outer bag of similar size to prevent accidental leakage, then into a sturdy container, such as a Styrofoam picnic cooler.
The plastic bag/Styrofoam cooler method is
advantageous in stabilizing the water temperature for
up to 48 hours. When transferring them to the
container, remember that fish need air, and fill the
container or plastic bag only about one-third full of
water. Use the water from the aquarium.
Remove the aquarium accessories; empty and dry the aquarium. Pack carefully, or have the mover pack them for you.
If convenient, take along in a separate container(s) as much of the water removed from the aquarium as you have room for.
Plants and snails from the aquarium can be carried along in plastic bags with a small amount of water.
Fish might become bruised while traveling. Liquid healing agents to put into the water are available at pet shops.
At destination, replace water and fish in the aquarium
as soon as possible. Add tap water a little at a time
to fill the aquarium to the proper level, letting the
fish adjust gradually to the new water.
If the fish must be moved in the aquarium itself,
remove about half the water, the aerator, heater,
hood, and anything else that might shift and cause the
glass to break. Cover the top with plastic film to
keep the water from splashing out. To avoid breakage,
take care that the bottom of the aquarium is solidly
supported while it is being lifted and moved.