I have been using a rubbermaid 50 waste bin as a reservoir with 2 continually running air stones.

The problem with air stones in a reservoir is that they don't stay put.

I recently found a solution to this. Place the air stones, while dry, at the bottom of the dry reservoir in desired location and then seal in place with bathroom caulking. It bonds well to plastic, is mold resistant, and doesn't break down in water.

I probably should have thought of this a while ago, but somehow this simple solution escaped me. Thought I would post it since I never found this solution online. Most likely there are postings with this solution and/or many others and I just didn't find them.... but here's hoping this post helps someone else who can't find those posts either.

You could also use a hot glue gun or just make a pvc pipe holder like this(middle of pics in first post)
http://forum.grasscity.com/general-i...step-step.html