How to Make a CO2 Freshwater Tank

A planted aquarium is one of the most beautiful things a person can create. It is an entire world submerged in crystal clear water. Shoals of colorful fish and gorgeous green plants dance in the currents.

Just like a landscaped yard, an aquascape (landscaped aquarium) needs to be trimmed, weeded and fertilized and have the proper amount of light in order to thrive. For inspiration, researching the aquarist Takashi Amano yields an endless array of beautiful planted aquariums.

When planned right and with proper upkeep, an aquascaped aquarium is a remarkable sight. Aquascaping and making your own CO2 injector are easy and important steps toward maintaining healthy aquatic plants.

Things You'll Need

  • Aquarium
  • 2-liter plastic soda bottle
  • Aquarium sealant
  • Aquarium air tubing
  • Drill
  • Scissors
  • Yeast
  • Sugar
  • Check valve
  • CO2 diffuser
  • Sand
  • Aquatic plants
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Instructions

  1. How to Set up a Planted CO2 Tank

    • 1

      First, clean the aquarium with bleach and water. Rinse thoroughly and then refill the aquarium with water. Allow it to sit overnight and check for any leaks that may show up. Failure to check even a new aquarium can cause a lot of water damage on floors and walls.

    • 2

      Drain the tank. Add a two to four inch layer of water-rinsed sand, sloping it slightly towards the front of the tank. The slope makes it easier to vacuum out leftover food and fish waste. You can add a layer of aquarium soil or common (clean) garden clay beneath the sand for extra plant nutrients.

    • 3

      Check the aquatic plants for snails, aphids and diseased or broken limbs. Remove any pests now so they cannot take over the tank later. Many stem plants can be rooted by sticking healthy cuttings directly into the aquarium substrate (the sand or clay in the bottom of the tank). They usually grow very fast and can fill in any bare areas of the tank.

    • 4

      Position the plants in their pots until you find an aesthetically pleasing arrangement. Remove the plants from their pots and carefully bury their roots in the sand. If lead weights or ties have been used on the plants, remove them now so they don't cause the plants to rot later.

    • 5

      Place a saucer or newspaper over the substrate when pouring water into the tank. It will displace the water and help to prevent the sand from stirring up. Slowly fill the tank with chlorine-free water.

    • 6

      Using the clean 2-liter soda bottle, add 2 cups of sugar and ¼ teaspoon of yeast. Fill the bottle to just over halfway with warm water. Do not use boiling water since it can melt the bottle and cause serious bodily injury. It will also kill the yeast.

    • 7

      Shake the bottle to mix the ingredients thoroughly. Drill a hole in the top of the bottle cap and sand down any rough edges. Cut the tubing in half with scissors and insert the check valve into both tubing ends.

      Make sure the check valve faces the proper way (read the instructions on the packaging). Pull the aquarium tubing through the hole (it should fit snugly) with the check valve on the outside of the bottle.

    • 8

      Use a small amount of aquarium sealant where the tubing goes into the bottle cap. Allow this to dry thoroughly before screwing the lid on the bottle. Once dry, put the cap on and tighten it well. Shake the bottle a few times to start the yeast solution activity.

    • 9

      Place the CO2 diffuser onto the end of the tubing and attach it to the inside of the aquarium. It must have good water flow in order to distribute the CO2 to the plants in the tank.

      Too much surface agitation can cause the CO2 to gas off too fast and leave the plants without sufficient CO2. Replace the mixture whenever you notice the CO2 bubbles have stopped forming at a decent rate.