Tiny bubbles rising from substrate

[gykramer]

I started a dirted 40-gal tank a couple months ago. For about the past month, I've noticed tiny bubbles coming up from one area of the tank from the substrate. I have a peatmoss and soil substrate covered with about 2 inches of well-washed sand. The bubbles are constant but only from the right side of the tank. I assume the bubbles are arisiing from some sort of reaction taking place at the base substrate level, but other than that I don't have a clue what's going on. Any ideas?

 

[Aiken Drum]

The bubbles will caused by microbes breaking down organic material in the substrate and releasing gas. Oxygen, nitrogen, maybe carbon dioxide or hydrogen sulphide.

Hydrogen sulphide would be the worrisome gas, and would smell of rotten eggs. Otherwise it's just natural processes happening, and they are common with organic substrates.

You might want to periodically push a stick or fork into the substrate here and there to prevent gas pockets forming, but otherwise unless there is a rotten egg smell or there are other problems in the aquarium i wouldn't worry too much. It's just natural processes happening.