Getting a new larger tank is like Christmas and a birthday both coming at once, for you and your fish. Bigger tanks offer more swimming and growing space for your resident fish collection, room to add more, and they make for a more impactful viewing spectacle. Here are some things you need to know when you're ready to move into a bigger tank.

Make Sure it Fits

Many hobbyists want a massive tank, but before we're ready to pull the trigger the first things we must ask ourselves: "Will it even fit through the front door, around corners, down cramped hallways, and even up or down staircases? Will the tank have to come in through the back of the house? Do we need to take a fence down or even use a small crane?" To know for sure, measure first. Measure the maximum width of your doorways and the maximum height. In a tight space, a tank or cabinet could be placed on its end and taken through like a refrigerator, so check door and ceiling heights too.

To take it even a step further, build a wooden frame with the external dimensions of your tank, and another of your cabinet. The mocked up frame can be constructed with inexpensive wood about an inch to inch and a half thick, or even cardboard pieced together with tape since the only goal is to see if you can get it through the house and into its final resting place. If it won’t fit you may have to remove a window or door frame, otherwise you may need to find a tank building specialist to come and build on site. Great, if you can afford it, but not realistic for most fishkeepers.

Weight... Need Support...?

When you are ready to move into a bigger tank you also need ask yourself "Is my floor strong enough to hold the weight? Does the floor need to be reinforced or supported? Will I need help lifting the tank?" When filled, a large tank can weigh half a ton or more. Even when empty, tanks and cabinets are very heavy.  A five or six foot tank may weigh several hundred pounds, so depending on the weight, it may need two, four, or even six people to lift it; you might even need special equipment.

With your team of tank movers point out any steps or trip hazards and place strategic supports along the route where the tank movers may rest some weight to take a small breather. If you have access to four wheel dollies or glass carrying suction pads, you can place the tank quickly and safely, without any damage or accidents. Be sure to log it in as a workout and reward anyone who can help with food and refreshments.

Replacing the Existing Tank

It would be perfect to have the new tank placed next to the old one to transfer water, rockwork, and livestock with minimal disruption. But, if it's not in the cards, here is what we suggest you have on hand to help make things easier when you are ready to move into a bigger tank:

Recomended Equipment

  • A large container or buckets to move everything from the existing aquarium into. Many prefer food grade trash bins.
  • A siphon to transfer as much clean water possible into the containers.
  • A net to catch the fish and then place them in the containers of water.
  • A small submersible pump, powerhead or air pump with air stone to keep proper gas exchange in the containers. Air stone would be preferred when moving tanks, since many fish often suffocate during tank moves.
  • A heater to keep temperatures stable.
  • Plenty of towels.
  • Optional: A tight-fitting lid on the vat the fish are being moved into to prevent any jumpers and to reduce stress

Prepping the new tank:

  • Move the new cabinet or stand into place.
  • Adjust its feet or use leveling shims to ensure the new cabinet is level.
  • Place the tank onto the cabinet with a leveling mat. Check levels.
  • Connect the plumbing.
  • Place new rockwork in - pre-planning the aquascape is suggested.
  • Add new clean sand.
  • Add new saltwater.
  • Turn on return pump, heaters and powerheads
  • Begin preferred method of cycling the aquarium.
  • Test parameters - once ammonia and nitrite levels drop to zero and the nitrate becomes present, it is safe to start adding animals into the aquarium.

Breaking down the old smaller tank:

  • Turn off all equipment.
  • Siphon as much "clean" water out of the tank into the containers that will hold the livestock.
  • Remove or frag coral from rockwork and place into their own container. Due to their ability to release toxins when under stress, a separate container is highly recommended.
  • Remove rockwork and place in a separate container. Removing rock makes catching the fish easier, just check that there are no fish stuck inside of the rockwork.
  • Place heaters, air stones and/or pumps into the containers.
  • Catch fish and invertebrates, then place into their own container.
  • Acclimate coral, fish and invertebrates to the newly cycled larger tank, then release.
  • Vacuum, dust, and clean the area the old tank occupied (if necessary), while you can.
  • Take your time, be patient, stay calm, and give yourself all day to do the move. Your fish need you to have a level head if they are to get through this. If you are unsure invite a fellow fishkeeper over to help.
  • Some tasks may take longer than expected, so think of a goal finish time and double it.
  • Don’t do tank moves at night when aquatic stores are shut in case you need something in an emergency.
  • Don’t be tempted to add a whole load of new fish too soon. Bacterial populations take time to expand so even if the tank is bigger the beneficial bacteria population won’t be.