Well, just as I feared; while we were on our long awaited two week vacation the fish spawned. Our daughter and her husband were "watching" over things while we were gone and somehow missed the cues of spawning. When the largest fish did a roll-over and was dying and the three newbies from last year had already died they called and we talked them through water changes.(they hadn't gotten around to reading the six page pond tutorial I left them). By some miracle the five remaining large koi did recover but I just feel really sad when I look in the pond. We kept them in captivity and failed them. It is the last time we go anywhere in the spring.