How to Make an Aquarium Bubble Filter

Fish rely on clean air absorbed by the water, in order to breathe.

Setting up an aquarium requires simulating a natural habitat within a glass tank. In addition to a good filtration system, adequate lighting, heating and landscape, you must supply your fish with the required amount of aeration or oxygen. Fish breathe the tiny bubbles you see in a fish tank as their supply of oxygen, which the water absorbs from the air.

Things You'll Need

• Margarine container with lid (15-oz., round tub)
• 20-oz. plastic soda bottle
• Marker
• Scissors
• Thumb tack
• Utility knife
• Air pump
• Air hose -- long enough to extend from your air pump to the tank
• Air stone -- small enough to fit in the margarine container
• Small rocks

Instructions

1. Remove the lid from a clean, empty plastic margarine container. Trace the mouth of a 20-ounce soda bottle in the middle of the margarine container's lid, and cut out the hole. Pierce holes all over the the rest of the lid with a thumb tack. Put the lid back on the container, and measure its height -- from the base to the top of the lid.

2. Add 1 inch to the container height measurement, and cut off the same amount from the top of the soda bottle, using the knife.

3. Pierce a hole anywhere near the outer edge of the container lid, making it slightly smaller than the diameter of your air hose. Push the air hose through the hole from the outside of the lid. Connect the hose end extending from the underside of the lid to the aquarium airstone. Put the air stone, with the connected hose, in the bottom of the plastic container.

4. Place the cutoff part of the bottle on top of the air stone, with the mouth pointing upward. Fill in rocks around the bottle, up to the rim, and put the lid on the container -- with the bottle's mouth poking up through the hole in the lid, along with the air hose. Connect the other end of the air hose to the pump.

5. Place the container in the aquarium, and turn on the air stone. Watch air bubbles float up through the mouth of the soda bottle.

Tips & Warnings

• To test the quality of the water, dip the tips of your fingers into the water in the aquarium and quickly move your fingers back forth to create bubbles. Bubbles don't pop instantly in poor water quality. Good water quality for most fish ranges from a pH level of 7.2 to 7.8. The rocks build up bacteria on the surface, which breaks down the ammonia from fish waste.

• A powerful pump with a small aquarium air stone could result in big bubbles, for a turbulent water surface your fish may dislike. A deep aquarium may turn small bubbles at the bottom of the tank into big bubbles on the surface.

References

• Freshwater Aquaria; The Ideal Freshwater Aquarium Setup -- Basic Concepts; Ruby Bayan
• FishLore.com: DIY Aquarium Filter
• Faq.thekrib.com; Aquarium Filtration; Bruce Hallman
• AquariumFish.net: Cloudy or Foamy Water
• E0.aqua-fish.net: How to use an Aquarium Air Stone

Resources

• The Inspired Aquarium; Jeff Senske et al.