Well the title/description says it all. Big brown bloches on the fan leaves, which, through time, get worse. I'm think it's some sort of nute deficiency or is it too much of something, i'm not too sure.

Any suggestions would be much appreiciated.

Heres a pic.
Click to view attachment

leaf spot fungus,get bio-cept,and do as it sayes on the tin...........
also wash ur grow show down with a weak detergent...
good luck............
this should not be fatal if treated rite