N def? Help please

Before and after pic

As your plant goes through the flowering cycle, it will start to get more and more yellow. This is normal and you should not feed your plant a lot of Nitrogen during the budding cycle. It needs a little bit but it needs P and K more, as well as Mg. What have you been fertilizing with? Your leaves don't look too bad, how many weeks has it been flowering for? The closer you get to harvest, the more yellow the leaves will get.

Some will start to turn brown and fall off, mostly the older fan leaves. This is normal also and you should not cut them off until they fall off on their own or come off with VERY gentle pulling from you. As it buds more, the plant will not look perfectly healthy like it does in your pic 1 but that is normal as it uses up energy inside itself in order to make bigger buds! Depending on how long it has been flowering for, that plant looks pretty good to me!

It's been flowering for about 4 weeks been using cns17 ripe used cal mag 5ml and nothing happened maybe try again thanks for your time

That sounds good, your plants look fine for 4 weeks into flowering. You're using the right fertilizers, just keep doin' what you're doin'!

You don't want your leaves to be as dark green as they were in veg phase when you harvest. Turning lighter green/yellow is natural and nothing to worry about. If it suddenly gets really bad quickly then you can repost here, but I think from what you are doing it should just keep slowly yellowing and some older fan leaves will turn brown and fall off as it gets closer to harvest time.

Thanks much I'll keep that in mind your help is greatly appreciated

yeah its nitro deff cos your going thru the flowering stage , and for all the newbs out there it isnt normal although it effects alot of people the plant shouldnt yellow at all.the yellowing is actually bad for your buds and u will get reduced yeild from it, leaves make your bud u want them all green and healthy.try doing a grow just using veg nutes and u will see the difference in yeild.

your first pic looks alrite but for only 4 weeks into veg those last 2 pictures are bad i would start giving them nitrogen now or u will have fuck all leaves left.

Personally I believe yellowing leafs in the very latter stages of budding is natural. I imagine it is how you would find a wild MJ plant looking in late fall, but im just guessing. Having said that, 4 weeks into flowering is not the latter stages of bud, and your plants do look a bit underfed to me.

Thanks imma give it another nitrex feed ....hopefully not too late