Koi Illness??
I have a 1500 gallon pond, the water checks are okay, For the past 5 days one of my Koi carp of 20 inches has put on a lot of weight and has episodes of sitting at the bottom of the pond for about 5 minutes with its fins spread out, not gasping for air, is feeding, however this fish has never behaved this way before, getting a little worried as it does not move when I approach the pond. Any advice would be gratefully appreciated
<Mmmm, may be just "egg-bound" temporarily, but could be sign of gut blockage... Do read on WWM re Koi foods/feeding/nutrition... and I'd remove the one fish to a large-enough separate system (like a kiddie wading pool of size) and add the equivalent of about one level teaspoon per ten gallons of Epsom Salt to the water... monitor ammonia, make daily water changes and see if this "moves" whatever is causing your fish to expand. Bob Fenner>