Hi everybody im new to growing and dont have much space i built a grow box which is actually working great everything was going great until one day i noticed my plant starting to go yellow and brown in some places its mostly at the tips and edges on the leafs some leafs are losing color but not brown yet i have no idea what could be wrong i water as needed and i check her daily but i cant seem to figure out whats going on i would really appreciate some help like i said this is my first time ever growing so please be patient sence im still trying to learn everything. Thank you every body