Thanks to all for the information on growing with lights. I find that my "new" fixture has separate controls for the pairs of metal halide lamps (tubes), so I'm experimenting with using just one of the three pairs available. The fixture came with pulleys that can adjust the height; I have it about 24 inches/60 cm above the top of the plants. As someone recommended, I placed the less sun-loving plants off to the side, not directly under the lamps. There is a large window next to the plants, but it's west-facing and gets little winter sun. I hope this succeeds in bringing along the South American bulbs, such as Leucocoryne, which have germinated like grass this past week. I find that at least some species of this genus do well in the bulb house in spite of a little frost. The same is true of coastal Californian bulbs. One wonders if these species, which now experience little if any freezing in nature, preserved some frost resistance from an earlier evolutionary stage. Jane McGary Portland, Oregon, USA