yellowing leaves during flowering,help!plz

[smokybear]

Have you checked your your temps, PH, nute levels? If not then make sure they are all ok.

If everythings good there, click on the plant problems guide in my sig. Scroll down a bit till you get to potassium. Do your leaves look like that?

thanks for the quick reply frist off i must say i have a cheap probe for checking nute and ph,its a ferrymorris brand it was all i can afford at the moment but,ph is bettwen 6.8-6.5 nutes i dont know.i have ff big grow and tiger bloom also i add some mg 15/30/15 cause i thought the 2/8/4 tiger blooms didnt have enough Nto sustain the plant during the entire flowering cycle,hmmm the temps are at 80/86 when light are on and 62/65 when off i hope that helps