How to Drain a Fish Tank in 6 Easy & Simple Steps

how to drain a fish tank

Although you might never have to, learning how to drain a fish tank is a skill you might find beneficial one day. For instance, parasitic infestations that no water change can address will demand emptying the aquarium to deep-clean it.

Several methods are available to remove water out of a fish tank, though some tricks are more tedious than others. You will learn in this how-to guide two ways to clear a fish tank of water, preparing it for relocation, deep-cleaning, or dismantling.

Step-by-step to Drain a Fish Tank


What to Prepare

The items depend on your chosen “how to empty fish tank ideas.” Overall, you might want to prepare the following.

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  • Garden hose or gravel cleaner
  • Buckets
  • Towels, mats, rags
  • Tarp (optional)
  • Fish net
  • Aquarium fish bags or a large container for the fish and other livestock
  • Cooler (optional)
  • White distilled vinegar
  • Spray bottle
  • Small plastic bowl


Step 1: Prepare your surroundings.


There’s a chance of spilling aquarium water on the floor during the initial stages of the draining process. Should this water get to your carpet or seep into small crevices, it can stink up your place and promote fungus growth.

So, grab your towels, rags, or mats and place them on the floor around the fish tank. It’d also be ideal to use tarps or similar materials to protect the ground surface against water spills.

Visualize your planned movements to get water out of a fish tank, including transporting the drained water to the garden or other parts of the house.

Step 2: Relocate your fish and other livestock.


Changing the water does not require transferring fish and other livestock to a “temporary home.” Draining or emptying the aquarium of water does.

Grab an aquarium fish bag and fill it about one-third to one-half with aquarium water by scooping it using a small plastic bowl. Repeat this step until there’s none left in the tank. Note that each bag should contain one fish only; otherwise, there won’t be sufficient oxygen.

Do the same with corals, aquatic plants, snails, shrimp, and other livestock.

Place the aquarium fish bags in a cooler if you think it will take you more than half an hour to drain the fish tank and finish setting up their new home.

Step 3: Disconnect all power devices in the aquarium.


Although you might use a pump to empty fish tank units, standard safety precautions dictate the disconnection of all electronic devices to and from the fish tank.

Please unplug all fish tank accent lights, filtration systems, UV lights, heaters, and other electronic devices and accessories. Most importantly, make sure the filtration pump with a water-cooled impeller is disconnected; otherwise, it’ll overheat when the water level drops.

Step 4: Keep fish tank accessories, decorations, and other items.


To empty an aquarium means removing everything, including accessories and decorations.

Remove fake (plastic) plants, driftwood, rocks, and other fish tank décor. We recommend washing these items under running water and scrubbing the surfaces with a vinegar solution, then rinsing them well before storage.

To prepare this cleaning solution, mix equal parts of tap water with white distilled vinegar and pour it into a spray bottle.

Step 5: Drain the fish tank.

There are two options to drain an aquarium: an improvised aquarium drain hose (or DIY siphon) and a gravel cleaner. Both methods are effective.

  • Step 5a: With a garden hose.


This method is more practical, especially for families with a garden hose. However, we recommend using clear, flexible tubing to allow you to see water movement from the fish tank to the bucket.

To drain a fish tank with a hose, position the bucket lower than the aquarium to let gravity do the job.

To siphon the tank empty, simply submerge the entire hose into the tank and coil it into circles. Wait until the bubble stops escaping from the hose, then cover one of its ends with your thumb.

Afterward, remove the covered end from the tank with your thumb still in place. Only when you place it in the bottom of the bucket should you remove your thumb. By now, the water should be flowing out on its own accord.

  • Step 5b: With a gravel cleaner.


Although a DIY aquarium siphon is perfect for households without a pump, it can only work when the tank is higher than the bucket. If yours is on the ground, you’ll need to use the pump of the gravel cleaner to move the water.

We recommend reading the gravel cleaner’s operation instructions to optimize its function.

Position the outlet tube in a bucket and the inlet segment in the fish tank near the bottom as you would with a regular siphon. Turn on the device to start “sucking” water from the aquarium.

Lift and reposition the suction apparatus periodically to facilitate fish tank drainage.

Step 6: Save the water drained for other uses.

You might want to prepare several buckets to accommodate the water drained from the fish tank.

While there’s nothing wrong with dumping aquarium water, it’s better to save them for other purposes, such as watering your plants. Besides, if it’s still in relatively good condition, you can re-use it to set up the new tank. This allows the fish to adapt to the new environment faster.

Frequently Asked Questions


Should I remove fish when draining the water from fish tank?

Yes, you must remove fish and other livestock when you drain or empty a fish tank.

We must point out that “draining” the tank differs from a simple “water change.” Draining the aquarium requires emptying all water from the container.

Meanwhile, “water change” needs you to retain 10%-20% of the aquarium water. Hence, “water change” does not necessarily mean “emptying an aquarium.”

If you only need to “change” the water, not drain it, there is no need to remove fish and other livestock. This action will avoid stressing the fish.

How often should I drain my fish tank?

It is unnecessary to drain water from fish tank units, provided you observe regular and periodic water changes to keep the aquaponics system clean. Hence, you may never have to empty an aquarium of water ever.

However, moving or relocating a fish tank might require emptying the water. Fully-setup aquariums are heavy, and water accounts for 8.34 pounds for every gallon.

Deep-cleaning the fish tank also requires draining it, especially for saltwater aquariums with coralline algae or glass anemone infestations.

Dismantling the fish tank and capturing a “challenging” or “sneaky” fish might also demand removing all water from the aquarium.

Other uses for fish tank water

One question that pops out from novice aquarists after they remove water from fish tank units is what to do with the water. You have several options.

  • Water your plants. Freshwater aquarium water contains nitrogenous substances plants need to grow and thrive. Fish tank water is also rich in beneficial bacteria that can promote enhanced nutrient uptake by plants. Note that the same doesn’t apply to saltwater.
  • Start a new aquarium by filling it with “old,” biologically rich, and nutrient-dense fish tank water. This trick is perfect for jump-starting a fish tank cycling process, making the fish environment ready for inhabitants faster.


How to drain a fish tank is a straightforward process. Although some folks might use the old-school method of manually scooping the water out of the aquarium with a plastic jug or bowl, a hose or gravel cleaner is a more sensible and efficient solution.

Siphoning might be a crude method for evacuating water from a fish tank, but it works. So does a gravel cleaner, although you might have to spend some money to get a decent device.

Regardless, emptying your fish tank of water is a cinch with either method.