By Cathy M. Rosenthal
When people prepare for a move, they box up the dishes, pack the dog’s toys, and grab the cat’s carrier—but often forget one thing: their pet fish. I’ve seen it time and time again—fish are left behind or given away, assumed too fragile to transport, or meet a worse fate when tanks are drained and the fish discarded. But fish deserve better.
Take it from someone who has moved more than 35 times—and relocated every single fish tank, including freshwater and saltwater—it can be done. And it’s not nearly as hard as you might think. After all, you’re going to break down the tank anyway. Moving the fish is just a matter of doing it safely and setting things back up on the other end.
While it takes more planning than moving with a dog or cat, it’s absolutely doable with the right prep. Your fish are part of the family too—and they deserve a fresh start right alongside you. Follow these steps, and you will be well on your way to getting your pet fish to their new home.
(And the fact that you’re even reading this advice? That already impresses me.)
1. Bag Them Properly
When moving fish, do not use sandwich baggies or zip-top bags—they’re too thin, prone to unsealing, and not designed for live fish. Instead, visit your local pet store and ask for fish transport bags, which are made from thicker plastic and designed to safely hold both water and air. Most stores will sell a few to you and may even show you how to use them.
Always double-bag your fish to prevent leaks. Place one bag inside another with the seams offset.
Here’s how to properly bag your fish for a safe trip:
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Fill the bag one-third to halfway with water from your tank.
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Gently place one fish (or a few compatible ones) into the bag.
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Then blow regular room air (not oxygen) into the bag until it’s about two-thirds full.
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Quickly twist the top of the bag several times to trap the air.
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Tie a tight knot in the twisted portion (like you would close a balloon), or use rubber bands to secure it. ( I think the knot is safer.)
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Then tie or rubber-band the outer bag securely as well. (This is how the pros do it and it’s especially great for long-distance or high-risk moves. Many pet owners (myself included) have often just placed one sealed bag inside another, both upright. That method still works in most short trips, especially if you’re careful. If your move is under 8 hours and you’re using the fish transport bags, either method is likely fine. However, the inverted bag method is used for a good reason. It offsets the seams and seals, so if one bag leaks (say, from a pinhole or a popped knot), the other bag isn’t compromised at the same point.It’s an extra layer of insurance, especially useful for longer moves or when transporting rare or sensitive species.
Pro tip: Use large bags when possible. More space = more air = less stress for your fish.
If you’re traveling long-distance, ask your pet store if they can fill the bags with oxygen instead of air—many can, and it can extend your fish’s safe travel time significantly.
Pro tip: Use larger bags when possible. More space = more air = less stress.
Saltwater note: Use only saltwater from your tank in transport bags for marine fish. If you’re moving corals or invertebrates, bag them individually in clean saltwater and label them clearly.
2. What to Pack with You
Carry all these items in your vehicle, not the moving truck:
- Your tank (empty) and all components (filter, heater, lid, air pump)
- Dechlorinator (for freshwater) or premixed saltwater (for marine setups)
- Ammonia neutralizer or stress coat
- Fish food
- Extra fish bags and rubber bands
- Battery-powered air pump
- Thermometer strip
- Towels or padding
- Fish net
- Styrofoam cooler or hard-sided cooler
- Water testing kits (especially for ammonia, nitrite, and pH)
- Optional: Extra buckets with lids (for transporting water or substrate), and an extension cord in case you want to set up the tank and there is no nearby outlet.
Saltwater note: Saltwater fish often need more stable environments. If you can transport 5–10 gallons of your original saltwater, it can help maintain consistency and reduce stress.
3. Label and Protect
Place your fish bags in a Styrofoam or hard-sided cooler for insulation and protection from bumps. Line the bottom with a towel and clearly label:
“LIVE FISH – FRAGILE – THIS SIDE UP”
Keep it upright and don’t stack anything on top. Keep this container in the vehicle with you, not in the back of a truck or trunk.
4. Control the Temperature
Weather matters when moving fish. Spring and Fall are the easist times to move with fish. But you can move in more extreme conditions.
- In winter, keep fish in the heated cab of your vehicle. Crack heat packs carefully—they can get very hot—and always wrap them in towels before placing them near (never on) the bags. (This bears repeating: Never place heat directly on any of the bags.
- In summer, keep them shaded and transport in your air-conditioned vehicle. Avoid direct sunlight and never place them in the trunk.
Tip: Stick a peel-and-stick thermometer to the outside of a bag so you can monitor the temperature during the move.
5. Limit Time in Transit
Most fish can safely travel 8–12 hours in transport bags. If your trip is longer:
- Bring extra dechlorinated water (or premixed saltwater) to refresh the bags as needed. Open the bag, add the water, blow air into the bag, and retie it securely.
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Many fish stores can fill your bags with oxygen—this can extend the safe time to 24–48 hours. Call ahead to check availability.
6. Skip Feeding Before the Trip
Do not feed your fish 24 hours before moving. Less food means less waste, keeping the water cleaner and preventing harmful ammonia buildup. Your fish can safely miss a meal or two.
7. Move the Tank Carefully
Drain and clean the tank, but don’t toss everything.
- Save filter media, gravel/sand, and decorations in sealed containers filled with tank water. This preserves the beneficial bacteria needed for cycling. First, you’ll need the tank as soon as you arrive. Second, moving trucks typically have poor suspension, and the constant jostling can cause the tank to crack or loosen the seals around its edges. Even a hairline crack can lead to leaks later. Transporting the tank gently and securely in your vehicle helps ensure it arrives intact and ready to reassemble.
- Saltwater note: Pack your live rock and any corals in water from the tank. Keep them moist, dark, and warm. If you can transport some of your live sand, even better—it helps restart the nitrogen cycle in the new setup.
8. Bring Backup Gear
A battery-powered air pump is a smart backup. It oxygenates the water if your trip takes longer than expected or you’re delayed in warm weather. They’re inexpensive, widely available, and very useful.
9. Reintroduce Slowly
When you arrive:
- Set up your tank as soon as possible with lukewarm, dechlorinated water, or pre-mixed saltwater for marine tanks.
- Check the temperature of the water and make sure it’s within the range for your particular species of fish.
- Float the sealed bags for 15–30 minutes to equalize temperatures.
- Slowly add tank water into the bags so your fish adjust to the new environment.
- Gently release the fish—and pour in the bag water too. It contains familiar bacteria that can help reestablish the cycle.
- Use your water test kits to ensure parameters are safe.
Saltwater note: Ensure salinity matches closely before reintroduction. A slow acclimation process (like drip acclimation) is recommended for sensitive saltwater species and invertebrates.
10. Temporary Setups Can Work
Can’t set up the main tank right away? Don’t panic. A clean plastic tote with a heater and filter makes a great temporary home.
- Use the water from the transport bags to reduce stress.
- Add a water conditioner (for freshwater) or a bacterial supplement (for either type) to support your fish.
- Limit this setup to just a few days, if possible.
Unless you’re moving overseas or face unavoidable restrictions, please don’t leave your fish behind. With a little extra planning, your fish can safely make the journey and thrive in their new home. And when you see them happily swimming again in their tank, you’ll know: it was absolutely worth it.
