Installing an Air Stone

Betta Bubble Maker, originally uploaded by devroka.

Q: MS wrote,

I recently rescued a Betta fish from being the leftover of a center piece at a wedding and I just setup a tank for the little guy in my apartment.I purchased 1.5 gallon tank and the tank came with an airstone system in it. Now I have been trying to read up as much as possible online regarding Betta, and I seem to be reading a lot of mix opinions regarding moving water with Betas.

I am generally concerned that the airstone would disturb my fish’s ability to build a bubble nest. Is there a proper recommendation on how often I should run the airstone, if at all?

Also how should I adjust the height of the output top of the airstone in relation to the top of the water? Should the water level be equal to the airstone output, or should it be slightly lower so the upcoming air slightly spills out?

Any help would be greatly appreciated. Great site by the way, it is very informative for me regarding me newly saved fish.

A: Great question. Betta splendens, unlike most fish, have a special lung-like organ called a labyrinth organ located near their gills. They share this special organ with other anabantoids like Gouramis and Paradise Fish. The labyrinth organ allows fish who are found naturally in water with low dissolved oxygen levels to gulp air directly from atmosphere at the water’s surface. Because of this specialized adaption, Bettas don’t require air stones to oxygenate the water.

Air stones are typically most helpful in aquariums with very little water movement. If you are running a HOB filter (Hang on Back) the water usually gets enough oxygen from the filter’s output. A tank with an under-gravel filter doesn’t get much water movement and may benefit from an air stone. Another reason for using an air stone would be to keep the water surface in a bowl without a filter agitated so unsightly detritus doesn’t form. Other’s choose to add air stones entirely for their aesthetic appeal, which can add quite a nice effect if hidden within the aquarium decor.

In terms of bubblenest building, an air stone will make it virtually impossible for the bubbles to stay unless you have a portion of the tank sanctioned off where there is no surface movement. Observing bubblenest building is interesting and impressive but not necessary. No harm will come to the Betta if he can’t build a bubblenest. In most cases, even the mild surface agitation created by the filter is too much for bubbles to hold.

There are dozens of styles of air stones so how you install them may differ slightly but in most cases there are four components important to installing an air stone. First, cut a small piece of air tubing (a few inches long at most) and attach it to the air pump. Then install an inexpensive reverse-flow valve. This will keep the water from siphoning out of the tank and onto the floor in the event of a power outage. Next, attach a longer piece of air tubing to the other side of the reverse-flow valve. To determine how long the tubing needs to be, consider where you will be keeping the pump and allow enough room to run the tubing all the way to the bottom of the tank. You can always trim it down if it is too long. Finally, attach the air stone itself to the end of the tube.

Remember, the water at the bottom of the tank gets less oxygen then the surface. To provide ample oxygenation to bottom dwelling species, you’ll want to attach the stone near the bottom or even under the substrate if you want to keep it hidden. I like to hide mine in the back under the sand or behind lush plant material so only the bubbles are visible.