Could also be rootbound, maybe some root rot, the soil could become very compact actually crushing the roots and not letting them grow. Probably not draining too well and that could cause some root rot.
Lit Up Reviewed by Lit Up on . FINNALY!!! My troubleshooting form is filled!!! HELP! S=Traditional Soil E-indoor E-Soil E-Plain Soil Mix CSL-Soil with Wormcasts (18%) + 80 soil + 2% rice E-Tapwater E-6.9 Water pH HRT-Source water EC (if hydro) E-2.5 months E-No fertilizer, yet. I used some N while they were vegging Rating: 5