Welcome Aboard, Just throw'em out, should get all kind of answers, pick the
one you like.

1st answer: Generally, Koi, especially large ones like to dig or root in
plant pots or just turn them over and make a mess of the pond, although I
have a couple and have had no problems of such yet, but there only 8 inches
long to date, goldfish tend to be a little more plant friendly but that's
not always true either. There may be more reasons than this but this tends
to be the biggest issue. Uless it's pretty deep you may want to consider
thinning out the fish a bit or really increasing the number of plants. Good
luck...Claude

Claude's pond http://home.fuse.net/ace883/