Tadpole/toadlet question

[stickytoes]

Just transferred my American toad tads into a ten gallon 1/2 land, 1/2 water. Their aquatic tank was oxygenated with an air stone. Their front legs are beginning to pop. Think I need to oxygenate the water still, or should they be okay for the last day or so of morphing as long as it's clean? Thanks.

[John]

You don't need the air stone. Incidentally, the air stone doesn't actually "oxygenate" the water. What it does is increase gaseous exchange at the water's surface by moving the water around.

I would be more concerned that they may drown - toadlets are very prone to drowning, so keep the water extremely shallow, with a lot of opportunities to get out of the water easily.

[stickytoes]

Alright, good. And thanks for the info about the air stone! So what does actually oxygenate water? And the water is only a few inches high, no worries. And plenty of rocks and a gentle gravel slope. Thanks for the reply!

[Paul Rust]

Alright, good. And thanks for the info about the air stone! So what does actually oxygenate water?

Water naturally exchanges gasses at the surface, so the short answer is that water oxygenates itself. Oxygen bubbles do not contribute other than they create more surface area for this exchange. What actually happens is it lets the water get rid of more carbon dioxide which in turn leaves more room for oxygen to be absorbed. The oxygen rich water at the surface sinks deeper in the aquarium and the carbon dioxide rich water moves to the surface. The point is...a filter that disrupts the water surface does the same thing, so does a waterfall. An airstone is not necessary.