| Sorry to be blunt, but here goes....
I share your wife's love for aquatic plants and am also developing a fondness for goldfish. The pond you describe sounds perfect for plants and goldfish. As a koi pond it will work for keeping a few koi for a year or so. However, you are just setting yourself up for trouble and heartbreak by trying to keep koi in that pond for the long term. Koi will out-grow the pond, proceed to uproot and eat all the plants, and eventually the pond will crash because it cannot handle the feed input needed for a bunch of large fish. You will have a constant parade of disease, death and replacement koi. To keep koi, you need something with a larger foot print, much deeper and a robust filtration system.
My suggestion would be to either (1) forget the koi and stick to a goldfish/plants water garden, or (2) build another pond for the koi. Both options can bring a lot of enjoyment and success.
-steve hopkins |