Snails can be both neutral and bad.

Bad in that complete a cycle of parasites
between birds, snails and fish.
And bad that they can clog pumps.

I've had them for years and years with no
problems. Koi seem to keep them at bay
in the pond but they show up in the filter
and are all over the frog bog.

They usually come in as eggs on plants,
they look like clear strips of firm jelly.

Robyn has a great snail information page
with info on getting rid of them, if you want
to.
http://www.fishpondinfo.com/snail.htm

kathy :-) www.blogfromthebog.com
this week ~ the rat-tail maggot!


Pond 101 page for new pond keepers ~
http://hometown.aol.com/ka30p/myhomepage/garden.html