How early into flower does defencies start to show?

Hey everyone.
At the moment i am at day 32 flowering and some of the fan leaves are yurning a yellowish colour with some brown spotting on the leaves. I know nitrigen Def is common with flowering plants but the brown spots im not sure about.
It seems like it is spreading upwards but not turning the leaves real yellow, just pale green, also with spots.
Can anyone help me out.
Thanks

Sounds like its a minor N def along with magnesium. N def is common mid flower if your only feeding high pk. A light dose of veg nutes may help and i would also feed some micros to counter the spotting. Hope that helps 1BMM

Thx man. I went and asked my grow dude at the hydro shop and he says I am not giving my plants enough water when im watering.
But thx for the help man, I was thinkin the same things as you. Im hoping they are underfed.

deffieciencys can show at as little as 2weeks into flowering, just give it alittle N in its feed.if your in soil add alittle blood n bone, or a tiny bit of lime=that would add suffiecent mag and calcium as well as other trace elements