I'd go with fluorescent bulbs spaced six inches apart, for a total of 640 watts (16 40-watt 4' bulbs, or 8 80-watt 8' bulbs). You'll get more even light and can place them very close to the seedlings. Buy a bunch of inexpensive two-bulb "shop lights" and attach them side-by-side to the underside of a wood frame, which you can raise as the seedlings grow (or you can support the flats on stacks of 1Ã4 boards and remove boards to lower the flats). A window fan, perhaps with a humidifier, would be good enough climate control. Try it first on a space about a quarter the size you have in mind and see how it goes.

if you have'nt used 400's before they get pretty hot and I think for a small space like that I would use a set up like ny is suggesting with the 16 40 watt 4 footers.cool white 4 footers.heat would be your down fall I think with going with the 400's and such a short space 2 ft is just not enough room I think so thats why I say this.good luck.

Go with the fluorescents for tiny plants and hang them close as described. The HPS can't be used very close to plants because of heat and the very small light source. Get an HPS system for more light at better efficiency if you want to grow them taller than a few inches.

Thanks, good stuff, but how many ft. candles per sq. ft. (sq. inch!) would a 10-day-old seedling (Microgreen) need anyway, does more light necessarily mean more weight here? Would using less wattage (Possibly incandescent or very low florescent) for the first 5-days, then moving them to a real excessive amount of ft. candles for the remaining 5-to-6 days work as well? IÂve heard some sprouts are grown 90% of their life span without light and then exposed to be greened before harvest. Is it possible to get good-to-equal output with half the light input for this product, can anyone expand on this thought?

Again, thanks for reading this!

It wouldn't be worth the hassle, or the wear and tear on the fixtures, to use lower-wattage fluorescents for germination and switch to standard ones for growth. The ballasts (electrical components in the fixtures) are designed for a fixed wattage anyway, I think. The ones Jungle_Fever and I mentioned are standard wattages.

For the same reason, although you could remove every other bulb during germination, there's not much point. Because seeds don't all sprout simultaneously, this could cause some of the early arrivals to become spindly as they reach for a distant light. Anyway, in addition to light, the bulbs provide heat that's helpful for quick germination.

To give you an idea, let's suppose you were to cut the wattage in half for 5 days, you run the lights 16 hours per day, and you pay 15 cents per kWh for electricity. During those 5 days, you'd save about 25 cents.

Keep your setup simple and don't try to fine-tune it too much. If you really want to save money, find a spot where you can do this outdoors using natural (and free) sunlight.