| Some of the folks who winter their koi indoors might have suggestions of what works for them. We do know that koi with exposure to sunlight develop better color, but that direct sun can be harmful. Bright shade seems best. I think a selection of artificial light that imitates the intensity of the shady side of a house would be about right. I am not familiar with studies of light color and the like in relation to fish development. But, I don't think you can go wrong using a full-spectrum daylight flourescent[I am familiar with such studies relating to the needs of aquatic plants. There are spectra that are optimal for different processes, but the differences between a 'natural daylight' flourescent, a bluish-light, a greenish light, yellow etc. are really not so great.] The real challenge in aquarium lighting is having the bulbs close enough to get appropriate intensity, without undue risk or over heating the water. Just some thoughts while we wait for those who have experience in keeping koi under lights. |