I'm pretty sure lucifer is right, I had the exact same problem, and after I transplanted they became healthier, however, some still died. So I would suggest doing it asap.
dontsmokecrack Reviewed by dontsmokecrack on . leafs drying then curling Hello my plant fan leafs are drying and curling up its affecting all my plants its starting from the bottom at works its way up some leafs look like they have been eaten! (Attached are some pics) Humidity bettween 35-55% Temp between 17.9 and 28.3 Fed them a weeks ago with hlaf specfied neuts (ironic grow and bloom growthtechnology.com) When i first fed them i saw signs of neut burn so i flushed them all. Run off ph 6.4 Oh and some leafs that look healthy just randomly fall off just like Rating: 5