Our garden ponds are artificial environments. This means that they need maintenance to keep the conditions acceptable for fish. Yes, carp (Koi) and goldfish are pretty tough but they do much better with the water temperature, pH and hardness in their optimum range and with a minimum of waste build up in the pond. Hydrogen Sulfide kills things very easily when in high enough concentrations. Parasites can knock out most of your fish in a few days if not caught early. We want our fish to be happy and healthy, not struggling to survive. The same goes for feeding, a healthy diet keeps them alive a lot longer.

Big Red has been out and about and grazing with the others the last couple of days - I am so relieved. May not have to quarantine after all - whew. He was definitely stressed about something though, not sure what. Mine are goldies - not koi - who are indoors over the winter. I moved them out early this year - mid March - and they all seemed OK until the new fish showed up a week and 1/2 ago. I guess what Im curious about is if in the wild they would travel in packs or schools and be "bonded" to each other.... do they relate to each other as indviduals or is one fish pretty much interchangeable with another fish to them. When I first put the new ones in it seemed the 2 groups mingled a little but for a couple of days tended to stick together, old fish together and new fish together. It's just interesting to speculate what if anything goes on in the fish mind. They are much more aware than I thought they would be.... they can distinguish between me who feeds them vs. my cat who wants to eat them.

When hungry, goldfish and koi will put anything that fits in their mouth that is thrown on the water. If they like they will chew on it, if they don't they will spit it out

When I was a kid, we're talking late WWII here, old farmers would toss surplus carp in the cow tank for later eating. Some would toss in a goldfish or two when available to amuse vexatious kids like myself. The tanks would often freeze, several inches deep, and, for the cows, they would hack a hole through the ice with an ax. I don't remember any dead fish attributable to the blows but then it has been 65 years.