Koi Pond

I made a terrible error yesterday afternoon. I was topping off the level of the pond, and forgot. I left the the hose running the well water into teh pond until the following morning. Effectively performing a complete water change to the pond. Fortunately most of the fish were fine. Tragically, our albino catfish could not handle the dramatic change. It may have been the levels of hydrogen sulfite that are in the well water. I am not sure if it was that or just the trauma of what was effectively a complete water change.
The catfish was found by my wife lying on his side on the bottom of the pond. At that point he was still alive, but barely. Thinkin that it may be high levels of hydrogen sulfite, we quicky set up the 50 gallon aquarium with tap water treated with water prep to remove the chlorine. We also equiped the tank with two bubble stones and moved the catfish into that tank. Unfortunately approximately 50 minutes later, he stopped breathing.
He is now resting soundly just south of the pond about 1 1/2 feet under the ground.

One of our fish died 4-1-03 How do I build a pond?

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