Pictures of my fcking yellow leafs wtf?

K i just got the digital camera , i toke a pic of the leafs its in my profile Grow4tho187's Marijuana Growing Profile , tell me wat can cause this type of attitude from my plant?

more info...

well last thread i had no pics and now i got some , my lower leafs have bin going yellow for couple days now.

https://www.rollitup.org/general-marijuana-growing/69984-if-no-one-helps-me.html

probably nitrogen def