Yellow, brown leaves, curling

¿En qué fase estás? Si estás en crecimiento, es falta de N. Añade abono de crecimiento Si estás en floración (a partir de 2a mitad) es algo normal y bueno! La planta absorbe los nutrientes de las hojas para engordar tus cogollos!

flowering/blooming add nitrogen it is in vegetable lower nitrogen [N] it is in the late bloom like 3/2 week before harvest leave it is normal for buds to feed from the bottom leaves so they get fat and leaves die/turn yellow in the process

Lower leaves normally go yellow as the plant gets older which is normal. If she is still in veg phase, it could be Nitrogen Deficiency, some Epsom salts will do the trick. Happy growing bud.