In article , DavidM
writes
Not sure why I said it would not a great pond, my apologies. Small still
water ponds would probably have less tolerance to over stocking. But as
you say, one fish can thrive in a balanced pond.

I've always fancied keeping a single large fish in a pond or tank. A
local aquatic centre kept a Giant gourami in their shop. He was a
monster, even by Koi standards.

Have you lost fish in the past to infection? Not that it's any
reflection on the pond keeping, I just imagine the risk of anaerobic
bacteria is quite high in a still pond.

No need to apologise - each to their own I never lost any fish to
infection but to next door's cat! My son bought 6 little Orfes 7 years
ago and the cat fished five of them! I have to confess I was more
worried about the cat puncturing the pond liner than the poor fish at
the time! - which is why I never replaced them. The current one is 10"
long now. The water isn't always still though. I run a fountain
intermittently, but there is no filter system other than the little
filter on the fountain pump that I clean out if the fountain spray
depletes, - that seems to be around every three years. At the moment my
yellow irises in the pond are just about to burst into flower.

Angela.