"rc" wrote in message
oups.com...
I've got a 400-500 gal pond with a 3ft waterfall. Its finally up and
running with plenty of plants and prob too many goldfish(21). The only
problem (other than maybe overstocking) is that I have very little
sunlight.
I want to expand to a second pond and am wondering wether they should
be connected for a larger total volume, or two separate ponds to keep
cross contamination to a minimum.

Fuzz


What type of cross contamination issues are you concerned with? If you keep
new fish in quarantine you can minimize the risk of introduced disease.
Maintaining separate ponds in close proximity won't help, disease in 1 pond
will easily cross to the other, from cleaning equipment, on your hands, etc.

As for adding sunlight, that is a double edged sword. The increased sunlight
will help you grow plants, include plants you don't want, such as suspended
algae. One possible brainstorm idea is to make a second pond that is
primarily plants, maybe a few fish to keep the mosquito levels to a minimum.

-S