Benign Vanilla wrote:

I've always feared the "toxic gases" from the pond bottom muck, but
everytime I stir that muck up in my pond (and admittedly in my aquarium
when I neglect it) my fish love it. They swim in it, they eat it, they go
crazy for it. I have never seen a fish die or even swim away in a funny
way.

I've got to agree with Ingrid on this one. Yeah, they love what gets
stirred up from the bottom, because it's full of little invertebrates, but
if it's bubbling, it's not healthy. Koi ponds don't tend to get to that
stage easily, because the koi themselves root about in the muck enough to
keep it from developing gas pockets, but if you neglect a pond long enough,
it'll happen.
--
derek