In CA, if an inmate had 8 months left in prison and got caught with marijuana how much more time will get added to that 8 months he had left?

Probably no more time added as marijuana is almost like tobacco now - we think that the penalties would be similar. But he will do think he will do much "harder time" for the balance of the sentence. He is probably in the SHU, or solitary now and it is our guess that he will spend several weeks there serving the punishment for having contraband.