jeremey, I am using the same light. Love it! Directions say to keep the light 12 inches above the seedlings which I am doing with great success. It is a 'cool' light, no warmth. This has led me to an important discovery. I have this light set up in an out of the way floor corner and the floor temperature stays at an even 60 degrees.

You will want to start your seedling in the usual way, on a 70 degree heating mat and then pot them when they grow their second leaves. Set potted seedlings under LED light. You will find that this cool light allows the seedlings to develop steadily and not put on the rampant, soft growth one experiences with florescent warm lights. This year I planted my tomato seedlings as I have done for the past 60 years. I plant the seedlings at their second leaf growth stage in a tall pot, filling the pot only half full of soil. (Tall Styrofoam cups purchased at Dollar Store work well. )Then as the tomato seedlings grow I add more soil. Using this cool LED light with no heat at a 60 degree air temperature I have watch these tomato seedlings stay 'tight', put on slow, steady growth and not get leggy and weak. This is an important discovery! This old dog has learned a new trick. Last thought...I find that using the LED light requires keeping an eye on leaf color and the possible need for additional fertilizing, especially magnesium ( Epsom salts).

According to the seller, it emits 25 watts of light. This isn't very much light per watts/ft so 1-3 inches probably won't hurt anything.

Funkyhat, wattage is a measure of POWER CONSUMPTION, not light emitted. LED fixtures use less energy to generate a given amount of light than do fluorescents. You get more bang for the buck. That 25W is a GOOD thing.

I'm aware watts is a measure of power used not light emitted, but if you know the light type and wattage you can make a reasonable guess.

In this case that light says, per the 'seller' on Amazon', the LEDs are set to draw 25w of power. This is not a lot of light output. Other systems have 100w hitting the diodes.

If you want a relative indication of power usage between flourescent and LED, your household light bulb is a good indicator. I have 900lumen bulbs in Halogen, CFL and LED. Halogen is 20-something watts, CFL 13W and LED 10W for the same 60w incandescent equivalent.

That light is not a good light. You'll get similar performance with two household light bulbs and superior with 3.

No, you don't. That 25W fixture is comparable to a standard T8 two-bulb fixture (of the same length, I've actually forgotten how big the fixture is and I'm not interested enough to look it up again) only it uses less power. If by "household light bulbs" you mean the old incandescents then you are WAY off, and if you are referring to more modern CFLs, you're still off.

The only LED fixtures I'm interested in are a lot bigger than that one. But saying it is "bad" because it is a 25W fixture is meaningless.