Oxygen stone...

[Scarab]

Was in the lfs the other day and saw this itty bitty aquarium by Tom Aquaria I think...not sure of the whole name, but I know "Tom" is in there somewhere. It's a little less than a gallon and comes with gravel, etc., and what they call an "oxygen stone" (not an air stone) that you drop in the water and is supposed to be good for one month.

Now, just so you know, I don't plan on buying this tank. But was just curious about these oxygen stones. What are they? Has anyone ever used one? Do they work? How do they work??

 

[Alien Anna]

Oxygen tablets or stones are useful if you have fish in an enclosed space, such as a fish bag. However, the way it works in a tank is that the oxygen is dissolved in the water at the surface - the more the surface is disrupted, the more oxygen gets dissolved. But once the oxygen is dissolved in the water, that's it - you can't squeeze in any more.

Oxygen tablets actually oxygenate the air above the fish tank. The bubbles they produce then disrupt the surface, allowing the oxygen to dissolve from the air into the water.