We have a 2000gal pond with seven very large koi and three babies from last year. The pond is rectangular (5X17 feet) and has four filtration systems which keep it sparkling clear. My concern is that our fish will spawn while we are on vacation and will perish from an ammonia spike. Last year they spawned after five seasons of no spawning. I thought that maybe they were getting too old to spawn (ha ha! silly me), but I was sadly mistaken. We ended up losing our largest fish some months later, and while I can't prove it, I feel that it was related to the spawn. Our adult children will be staying at the house and watching over the pond and I am hoping that they will not have to deal with the mess and water changes. I have been reminding my husband not to overfeed the fish, but they know just how to give him that "I'm starving look" that he is a sucker for. While reading through many of the posts I seem to see very little on spawning; does anyone have any experience with something I can do to discourage spawning?