Too Little Light For Seedlings?

[MitchellM]

For a new tray of mixed Southwest desert and Andean species I have two clamp lights with 13 watt bulbs. The bulb on the left one is 11 to 13 inches from the soil surface. It's visibly dimmer from my first tray about 12 inches from two T5 tubes shaded by tissue paper. Are my seedlings going to be etiolated? I have another T5 fixture coming in the mail but these are germinating faster than I expected. I can probably find a way to support these lights closer or switch to bigger bulbs. I have 10 spots free in the tray lit by T5s that I'll probably move the biggest seedlings up to today.

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[esp_imaging]

I don't know if they are too dark - if your other set up is shaded by tissue paper, then you can be plenty darker and still be OK.
Moving the lights closer is very effective - 2x as close can equate to 4x as bright. Closer and directly overhead will help.
Making side reflectors from silver or white panels is also very effective - if you can bounce light back in from the sides or top it will make a difference if the lighting is a little less than optimal.

[greenknight]

13w CFLs? Yes, a little closer would be best, but 2 of them should be enough for that 1 tray.

[7george]

13w CFLs? Yes, a little closer would be best, but 2 of them should be enough for that 1 tray.

I agree with greenknight, bring seedlings or lights closer. Find a way to control the temperature in that enclosure. After several months the light might be insufficient again and you'll have to change the setup again like removing the cover or placing those under real sunlight.

[MeloMet]

And above all, use trial and error. Seedlings grow too slowly to etoliate in just a few days, even a few weeks in some instances. Seedlings need more light as they get older, so for the first days/weeks, your current setup is plenty. If you notice they start stretching once they grow, add more light. If they start to turn red/purple, move them farther from the light.

Have fun!