Microbubbles...
 

For those of you who offered advice a couple days ago on my dying torch (thank you, but its still going downhill), I throw out another question: how deadly are microbubbles? And could they be the cause of my dying corals?

While at the LFS today we were brainstorming and the guy mentioned microbubbles being harmful. Then I realized I had seen lots of these in our tank, in fact the powerheads seem to be frequently collecting and spewing these out. I figured out they are coming up from the return line coming out of the sump, and think I might have found a likely air leak spot as well. That will be tomorrrow's project to fix; however has anyone else had experience with microbubbles killing stuff? Can corals recover after the problem is corrected?

Not really. They're more of a visual nuisance than anything.

I've read that a buildup of microbubbles on the undersides of coral can start necrosis and eventually kill the whole coral.... anyone agree with this or seen it happen?

micro bubbles irritate the coral never allowing full polyp extension

But seriously, what kind of microbubbles are we talking about here?! Is it like a horror film for corals? Or just irritating to look at? I doubt that microbubbles could or would cause the decline of an otherwise perfectly healthy coral....unless it were extreme.

Well there aren't a huge amount.. and I'm actually not convinced they're sticking on the corals either. I fiddled with the system today and I think I reduced the bubbles, though they're not gone... they're coming from my sump pump, or from somewhere in that return line.

I was wondering about microbubbles recently too, as I'm getting them from my canister filter. I did a search here on Canreef, but couldn't find an answer, one way or the other. I did another search elsewhere (Google? I forget.). Anyway, I found this: (Myth #14).
http://www.reefkeeping.com/issues/2004-01/eb/index.php

Cheers,