Started under CFL how soon can I put them under 400w MH

I noticed that the last time I moved some seedlings under the HID lamp they were kind of shocked then turned deep green and blew up like crazy. Except a few didnt take off and I think they may have been too young? They had just barely started to grow their 3rd leaf set. The ones that took off had completed the 3rd leaf set. Is it really that important to wait? Dont some people start seedlings under HID lamps? Im using a grow tent and I cant extend the 400w light more than 3.5 feet from the grow containers so Im weary about putting a seedling so close to the light. What do you think?

I start all my seedlings under hps, it has never been an issue. It's not the light, I would say it was heat. Do you have any heat damage? Burned tips, dried leaves, that sort of thing. If I had to guess, I'd say the light was baking the soil/rockwool/whatever and cooking your root systems. That's the best I can do without pics or more info.

it depends how big the CFL is that your starting them under. If your using a small one, or not giving the plants lots of light then they can develop very thin papery leaves. If you were to then put them straight under your HID they could experience shock. Best thing is what your already doing, when you move them under the HID, try to allow as much space away from the light as is possible, at least for the first 24 - 48 hours. After that they should be ready to deal with the extra workload.

Yea I haven't had any problems since I moved them from a 200w CFL to a 400W MH. As a matter of fact they loved it. I think I was just being overly cautious.