I put KOI fish in my wishing well pond, but the Neighbors cat had them for dessert, for 3 months she had not bothered them so I was so upset when I found her eating one of them. I no longer have fish. Too tempting to the cat.
Had not thought of the chemicals hurting them but I did not use many chemicals in mine, especially since it is constantly moving, recycling through the line, I tear it down and clean it good in the winter months. And I did drop some tablets recommended by local extension staff for ponds/water gardens but I purchased them at PetSmart so I am sure they were safe for pets. They have a good selection of this type of products at Petsmart (a local pet superstore- the only one we have currently).
Deidra