Bug Zapper

I put a light over my pond at night so my Koi can eat the insects that fall in the water. Is this a good idea? - Davis

As long as the zapper mounted correctly so it won't fall into the water and the amount of bugs that end up in the water don't foul it up, then go right ahead.  Bugs are full of protein, vitamins and minerals (Koi find them very tasty too).