Nirvana White Widow (F) nute burn or deficiency?

I have been reading how white widow can be very temperamental with feeding.

I'm hoping someone with WW experience can recognize the problem.

Out of 6 plants three look good, one is a little dark and two are all f**ked up.

They are ready to go into flowering (about 3 months old right now), are in Ocean Forest with 30% perlite, under a 400 MH, in 5 gal pots, watered every 4 or 5 days with RO + calmag (whenever they get dry), pH'd around 6.8 (runoff pH is fine), fed occasionally with FF bigbloom and a veg nute, both at half strength, but have been transplanted every month or so into a bigger pot and had more FFOF added, which should be taking care of the nute requirements. I have actually burned them in between transplants just by giving them full strength veg nutes. Ambient temp is between 60-75F (did get down to 55 a few times over the last few weeks).

Please don't anyone link one of those ridiculous low-res hand drawn diagnosis charts that have multiple drawings that all look alike.

Other grows never had these issues. Perhaps they were just much easier strains.

Thanks so much for any insights!

v Leaves on top and mid upper colas v

v This guy is really dark with subtle brown spots. Much darker than the others, my thought was N tox. v


v Yellowing v

I am a noob but im just trying to help. I was reading this site (not sure how reputable it actually is) and under "boron deficiency" kind of felt like it was in relation to your issue. I would read it real quick and see if anything there pertains to your situation as far as causes of this deficiency and what not. Good luck man, im always interested in the outcomes and fixes for issues!

http://www.growweedeasy.com/marijuana-symptoms

Those low temps might have something to do with it. Don't let it get below 68.

Carolina Dream'n said:

Those low temps might have something to do with it. Don't let it get below 68.

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I would disagree, although i don't have any rep, i do know that the rule of thumb for outdoors planting is when the weather hits 70 degrees during the day and a minimum of 60 degrees at night, at that point is the sign to go ahead and start outdoors, meaning that even a baby can handle this temp. Although this will slow growth, its unlikely it will show signs of stress because of it, but they can survive with 50 degree lows no problem, its just not ideal. What i do know is that anything under 40 degrees will cause tissue damage.

We all are valued our own opinion. We just happen to disagree on this subject. I never let my garden get below 70 degrees. Lights on or off. Plants stop transpiring and absorbing nutrients around 65 degrees from my understanding. Please someone correct me if that's false information.

I am working on a heater system, should eliminate these temperature swings. However the problem was there even before the recent cold weather. It has just got worse since.

Thanks much for your assistance!

Ppm of your feed with calmag? And are you using organic cal-mag. If not you probably killed all microbes and now the plant can't access nutrients.