I'd like to hear the answer to your question too. I'm trying to grow cilantro on my kitchen counter under a compact florescent. It might do better under a MH HID bulb and be less inclined to go to seed, but I can't find a small counter-top fixture or one that's reasonably priced.

See this thread for some options.

HID fixtures are generally more efficient than fluorescent lights, meaning that you get several times more light for the same wattage. After you factor in electricity costs, the HID lights and bulbs are worth the extra money. Another big advantage is that the light from HID fixtures penetrates more deeply; fluorescents have to be very close to the leaves, so they can only really grow plants to about 4-6" tall.

Also worth considering are T5 (narrow bulb) and compact fluorescents. They give off less heat than HID lights, so can be placed closer to the plants, but are very bright. Worth considering as a middle ground.

Thanks. Money is the factor in me considering fluorescent over HID. I already have the fluorescents in my basement, so I will just start with those. I read they are good for starting seeds at least.

Yes, fluorescents are fine for starting seeds. Use a small fan to create a breeze; that will help discourage mold and rot. And don't let the growing medium get too wet. With fluorescents and full-sun plants (such as herb or veggie seedlings), it's very important to keep the foliage as close as possible to the bare bulbs. Half an inch to an inch away is not too close.

Garden centers or IGS sell seed-starting trays, cell packs, and humidity domes. The domes are very helpful for germinating. If you use them, remove them for an hour each day to allow the flats to air out.

If you're planning on planting the seedlings out in the spring, it's important not to start them too early. They'll take better if they're still small.

Good luck! Happy growing.

Half an inch?? Wow... I think I'll go 3". Too afraid of a short when I'm not home. I have a cat.... he's REALLY not intelligent...

I have used those awesome seeding domes before. Good call on the airing them out idea. The first one I had wasn't air tight or anything, so it was fine. Second one.... It was cool looking after a couple days!!

And the plants are staying inside. I'm starting them in rockwool and then moving them to a lettuce raft hydroponic system.

Don't worry about a short from the plants touching the bulbs. Only the ends get hot, and the worst that will happen is you'll singe the leaves. You want to keep plastic away from the bulbs though!

Sounds like a pretty serious setup. Please post pics when you've got it going.

Also check out the Growing under Lights forum.

By the way you want to put the lights on a timer to be on 16-18 hours per day.

Growing under lights forum.... this site really rocks! I'll throw up some pictures in the hydroponics forum when everything gets up to speed. 2-3 weeks. Thanks for all the info!

nygardener, correction, fluorescent lights are more efficient than HID lights. But HID lights can direct light in a more concentrated area if that's what you need.

Here is a link that might be useful: efficiency of HID vs fluorescent light

I'm not sure what the author of this article is talking about; it looks like he's concerned with industrial applications, which have much lower light levels than those needed for plants and lights that are mounted much farther away.

But it looks like the efficiency difference is smaller than I thought -- more like a factor of two. HID lights produce 100 to 140 lumens per watt. Fluorescents produce 50 to 80. HID lights get dimmer over time (and so should be replaced after about a year of use as grow lights), but so do fluorescents. Concentration is a function of the reflector; either can direct light in a concentrated area.