When should I harvest?

I'm not sure why this plant is dying... all the leaves are drying out and I have no idea why. please help! trich formation sucks too!!! im kinda scared its gonna get all messed up when im so close to harvest

i thought it might be magnesium deficiency, but now i have no idea. sucks too, cuz up until now it was doing great, but over the past 3 days it went from very healthy to this... its really kinda depressing

'Plant Problems' is where you want to ask this next time. You'll need to list more information if you want to get a members to give you detailed steps you can take. Hopefully this link will work: Troubleshooting Form

I've had trouble with linking to CannCom articles in the past, so if the link takes you nowhere, just head over to the Plant Problems forum. It's the only sticky in there, I think.

Follow that link, but my rookie opinion is over nuting. You should provide more info such as soil/hydro, pH, temps, etc. to get more help.

well i keep my ph at around 6, the temperature is a lil high, but it doesnt get over 80 F. my tds meter says the nute level is 1200, and I usually feed it 1000-1400 in flowering. i use dynagro bloom usually 2-4 mL per gallon, which is usualy 900 tds, and then I add maxicrop 2 mL, and thrive alive b-1 2 mL, or just until the tds is where i want it. what do you think?

and its also a hydro grow. just a basic reservoir setup i designed myself with a bin with the light sealed out and 2 12" airstones inside.

How old are the plants?

well i put them into 12/12 on the 22 of december. so they are only about a month into flowering.

any ideas? i know the light isnt too close, cuz the plant has like 4 ft. to work with, and the temp. at plant level is mid seventies. The leaves around some of the tops are just drying out... im at a loss

more pics... it looks real bad, help me please! i would jsut cut my losses and harvest now, but the hardcore trich formation hasnt even started yet... wwsd?