We definatly need to know;
how much water how often
have the plants ever dried back
ec in and ec of the run off as well as the PH in and PH out, the PH is really important!
did you buffer your coco?
what kinda light you using, how close, full power?
how long have you has these symptoms?
were they already hurting when you got them? all of them cuz while the other ones look better they not looking 100%
have you grown in coco before?
have you had problems before?
have you changed anything in your environment since getting the little ones?
you should be running higher hum with LEDs, definatly want to run VPD calculations if you want maximum
little book work for ya, most folks here thinking its something to do with the roots/soils not the enviromentals....defiantly read up. heres aqua's thread on coco
Ok writing this cause i see this issue often and rather have a thread to link than explain this each time. This is not my work but a collection of info from many members here and I have put into practice myself. So first off COCO is NOT soil. For best results we want to keep it saturated...