Collect Your Supplies in Advance
You have to transport your tank empty, which means having a plan in place for moving everything inside of it, including your fish, equipment, plants, and decorations. As such, your first step when moving a fish tank is to gather the essential supplies that you will need to make this happen. Some of the items on the list you probably own already; others you’ll have to go pick up in advance.
Here’s what you need:

Buckets or plastic bags or containers for fish. Small fish can be moved in plastic bags secured firmly at the top with a twist tie, provided you only have to travel a short distance (an hour or less). You could also use small plastic containers with lids. For larger fish and/or longer moves, you’ll want to use clean, 5-gallon buckets with lids.
Buckets for plants. These will need to be submerged in water from the tank during travel.
Packing tape or duct tape. For securing lids on buckets or plastic containers, if using.
Fishnet. For transporting your fish from their tank to their transport container.
Siphon hose. For removing water from the tank.
Other packing supplies. You’ll want to be sure that you have plenty of packing supplies for transporting equipment, decorations, and the fish tank itself. This includes air-filled plastic padding, packing paper, foam board insulation, and moving boxes (cardboard or plastic).
Don’t forget to account for moving the fish-related items that you store outside of the tank, such as fish food, aquarium test strips, water dechlorinator, and the table or other structure your tank sits on top of.

Move Your Fish Into Their Transport Containers
Regardless of whether you’re planning to move your fish in bags, plastic containers, or buckets, you’ll have to move them into their transport containers early enough that you have time to take the aquarium apart and clean it. Keep in mind however that fish are prone to stress when moved outside of their environment. To help minimize that stress, wait as long as you can before moving them into their transport containers. Use water from the tank to fill the container they’ll be traveling in, and be sure to leave air at the top. This will ensure that their environment is as comfortable and close to normal as it can be. If using buckets, you can put three or four fish in there together.
Stop feeding your fish 24 hours prior to moving them into their transport container. This will help keep the water clean during the move. (Don’t worry, fish are just fine to go without food for a day—and even up to a week, if they’re healthy.)

Get the Tank Ready for Travel
Moving a fish tank is just as much about moving the structure as it is about moving the fish themselves. Once your fish are safely in their containers, get to work on prepping the rest of the aquarium for your move.
Place plants in buckets and fill with water from the tank. Leave air at the top so water doesn’t spill out.
Siphon out remaining water and put it into a large, sealable bucket if possible. You’ll want to fill the tank back up later on with as much of its original water as possible.
Wipe down decorations, dry them, and pack them. If they’re fragile, wrap them in air-filled plastic padding and/or packing paper before packing.
Transport any pebbles or sand at the bottom of the tank to a bucket or other type of plastic container.
Remove all equipment and wipe it down and dry it if necessary. Keep the filter damp. Pack all of your equipment carefully.
Wipe down the tank and dry it completely.
Be sure to label all of the boxes containing decorations, equipment, and other supplies. You’ll need to put your fish tank back together as soon as you arrive at your new home, so it definitely helps to know what’s where.

Pack Your Tank
As you might expect, aquariums are very fragile and need to be handled with care. A crack or other damage during a move means your aquarium will be unusable in your new home, so take the time to pack it as securely as you can.
Take off the lid and wrap it in air-filled plastic padding. Secure with packing tape.
Cut foam board insulation to size and place it at the bottom of the tank. Fill the tank with towels or packing paper.
Wrap the tank in air-filled plastic padding and place in a moving box. Put foam board insulation around the sides, in between the tank and the box. The box should be large enough to accommodate the aquarium and insulation, but not so large that the tank has room to shift around. If there is space around it, use packing paper to fill in the gaps and help prevent it from shifting during transport.
Make sure to seal and label the box. Place arrows on the box showing which side is up so that the tank doesn’t end up upside down or on its side during transport.

Load Everything Up
On moving day, you or your movers will want to load the tank and its associated boxes onto the truck, being sure not to stack anything on top of the box housing the aquarium.
Moving trucks are generally not temperature controlled, so as a safety precaution always move the buckets with your fish in either the cabin of the truck or in your car. Prop them up and secure them so that you don’t have to worry about them tipping over during travel.

Put Everything Back Together
Putting your fish tank back together is one of the very first things that you want to do when you arrive at your new home. The less time your finned friends spend in their moving containers the better, so take on this task even before you start to unpack other essentials.
Figure out where you’re going to put the aquarium. If you’re not sure of a final resting spot yet, at least narrow it down to the room it will be in. This is where you’ll want to set up.
Unpack the tank and give it a once over to make sure that there are no cracks in the glass.
After you’ve confirmed the tank is good to be refilled, start the process of rebuilding your fish habitat. Put the pebbles or sand down first and then set up your equipment. Place decorations and plants back in the tank and then refill with the water you brought over in buckets.
Using the fishnet, gently transport your fish back in to the tank. Pour the water from their moving containers back in to the tank, removing any waste first if necessary. If you need more water to fill up the tank, get some from your tap and dechlorinate it before putting it in there.
Wait a few hours before turning on your heater and pump. This will give the water time to settle and get to room temperature.