We have connected ponds. The larger pond houses the koi and the lower
pond
houses the goldfish. We have found that the eggs travel and there are
a few koi
that have made it to the lower pond and also into the veggie filter.
Also the gold
fish have migrated to the koi pond. That is the only problem that we
have had.
When we tried to filter the water flowing between the ponds, it
continually was
clogged (seveal times a day) so we removed the filter.
Bonnie
NJ