Seedlings Require Help..

[murihikukid]

Hi...I would be sincerely grateful if my posted photos of a tray of plants (same tray taken from different angles) could be looked at and advice re what next....
Unfortunately they could not be raised as I planned and I am concerned about how spindly they are and how I can rectify this if possible..Up to this point they have been grown inside under lights and have received about 1/3rd of a cup of a light Miracle Gro mix each every 7 days...
So I am wondering if they require some other fertilizer.......should I put them out in my greenhouse under natural light and even retransplant them into new soil in big containers out there...
I do have a second tray that is now growing the same ..IE too spindly ...The plant trays have been raised up to the lights as close as possible to the top of the seedlings ....Maybe they are lacking in nitrogen?? My understanding of fertilizers and best ones to apply is not good but hopefully somebody can just give me info that will help...
Thankyou Ron