How To Add Water to an Aquarium

Young girl looking in fish tank
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It's very exciting to come home with a new aquarium and everything that goes inside. But sometimes the assembly and filling step can feel intimidating—especially for of first-time aquarium owners. Fortunately, the process is actually quite simple. As long as you carefully review all of the instructions, double check that you have all the required supplies, and make sure anything you're adding to the tank is thoroughly cleaned, you'll create a beautiful and healthy habitat for your fish. If you're still feeling a bit unsure, ask a friend or family member who has filled a tank before to give you a hand.

Filling Your Fish Tank With Water

Set up the aquarium, filtration, heater and lights according to the instructions provided with the aquarium equipment. Rinse the aquarium gravel and all decor items that you will place into the aquarium. Now that you've fully prepared the aquarium, all you need to do is follow these quick and easy steps and safely fill your aquarium with water. You'll want to set aside about 45 minutes (allow more time if you're filling a very large tank) to complete this process.

Supplies:

  • Aquarium and equipment
  • Water conditioner
  • Clean bucket
  • Clean plate
  • Washed gravel

Instructions:

  1. Purchase a bottle of aquarium water conditioner (dechlorinator).
  2. Purchase a bucket and label it for aquarium use only. Aquarium buckets should never have soap in them.
  3. Fill the bottom of the tank with the washed gravel to a depth of two to three inches.
  4. Lay a clean plate on top of the gravel. Be sure there is no soap residue on the plate. If unsure, soak it for five minutes in a 10% bleach solution, rinse thoroughly with running water, then let it air dry before use.
  5. Let cold water run from the tap for a few minutes to flush out any minerals or residue from the lines.
  6. Fill a clean bucket approximately two-thirds to three-fourths full with water.
  7. Slowly pour the water from the bucket onto the plate in the aquarium.
  8. Repeat steps six and seven until the tank is half filled with water.
  9. Add plants and decorations. You can add other accessories (like larger rocks and figurines) to the tank at this time—just make sure they're thoroughly washed and dried before putting into the tank. It's recommended to only add accessories purchased from an aquarium store as found rocks may alter the pH of your tank.
  10. Install the heater and filter, but do not plug them into the electrical outlet yet.
  11. Repeat steps six and seven until the aquarium is completely filled with water.
  12. Remove the plate and add water conditioner according to package instructions. Now is a good time to also add bacteria starter.
  13. Start the filter and heater, and let the aquarium run for at least twenty-four hours before adding fish.

Aquarium Assembly Tips

A few more things to keep in mind as you assemble your aquarium:

  1. Old buckets may be used if they haven't previously been used for chemicals and are thoroughly cleaned with bleach, rinsed well, and allowed to air dry.
  2. Fill your buckets only as full as you can comfortably carry and pour them.
  3. Before purchasing fish, be sure your tank is the appropriate sized habitat for the species.
  4. Check out this aquarium design tutorial if you aren't sure what you'd like to include in your tank.