standing

hi all, some of my seedlings have drooped over and are no longer standing up by themselves what could be the cause of this??

Hi there, I have added a small laptop fan last night to have a little breeze on the 10 day old seedlings. I kept the fan on overnight and noticed this morning the plants had changed their color into a more darker green color and also the leaves went from horizontal to angled at 45 degrees. Just...