Lighting for seedlings

[Scott_R]

Last year I bought several of these. The seedlings came in somewhat tall and stringy, but it's entirely likely that I'd spread the light out among too many things, had them too high up, and didn't have them on long enough (I can't recall how long exactly, but very likely not more than 12 hours).

So, this year I have three of them focused on a 10x20 seedling tray, about 7-8" above it (which is as close as I can get while using one of those clear plastic "greenhouse" hoods). They're on a timer for 14 hours (6 AM to 8 PM); the setup is in a basement, so there isn't significant sunlight getting in. I have the bulbs in those basic utility clamp-light setups you get at Home Depot; I removed the fixtures' reflectors, since the bulbs already project their light downwards and this enabled me to group the lights very close together so I could focus all three on the tray.

So... the question. Any way to know if these bulbs are actually any good? The reviews were excellent, but then again a) there could be a bunch of biased reviews (from the manufacturer or seller, or from people "encouraged" to give reviews in exchange for stuff), and b) they could be simply uninformed and not realizing they're getting subpar results.

My seedlings now range up to 2, nearly 3 inches (different plants, seeded different times, so different results) and if I need to enhance the lighting I should do so now.

 

[Scott_R]

Nothing?

 

[Tech]

You can determine how effective they are by checking the node spacing on the plant vs plants of the same speices from a greenhouse or proper grow area and comparing them. Longer the node spacing is or greater the gap is, the worse the light is, and the tighter node spacing is or how compact the plant is = better lighting. Your lights too far away from your plants for that test to be effective though. Another test would be to flower a tomato out and see how it goes.

tight nodes, compact growth = good light
seedlings that are tall lanky and spindly = poor light or light that isn't close enough to the plant for optimal growth (hense they stretch and reach for the light becoming spindly.)

For instance, my metal hallide fixture grows peppers more compact then most nurseries do under the full power of the sun, though they do have less daylight hours to deal with. Where as most shop light fixtures can't compete with nursery growth but still fair quite good, and you're right led lights often have a lot of false advertising associated with them.