Interveinial yellowing showing up badly near buds

Hey GC,

I'm 39 days (5.5 weeks) into flower with my Super Lemon Haze. I'm growing in hempy buckets (with about 15% vermiculite and 85% perlite) and I'm on the Lucas Formula, under a 400w HPS. My temp

This yellowing started at least a few weeks ago, probably a week or so into flowering. I stuck to the lucas formula pretty strictly all while maintaining a pH in my reservoir of 6.1 My ppm was usually between 920and 960ppm. I have since bumped it up (starting about 2 weeks ago I think?) to about 1100 after reading in a couple threads that the lucas formula can have problems with larger plants and scrogs, due to not enough Magnesium. Since the yellowing was going on since around the time my ppm was BELOW what the target ppm that Lucas laid out for .5 EC conversion (I think it was ~950 or thereabouts) I figured it was a deficiency not a burn.

But the yellowing got worse, until the point where I am today. I noticed the tips started burning after the last couple of waterings (about 4-5 days ago) so I have since brought the ppm of my res back down to 970. I'm going to water again tonight, but I'm really at a loss at what to do because at this point I can't figure out if I'm giving it too much or not enough!! Either way I'll probably end up flushing, but I'm not sure where to set the nutes at. What do you think GC??

Other info:
Lights on: Temp ranges from 76-83, most of the time sitting at 80
Humidity ~30-45%
Lights off temp - 65-75
humidity - 45-60% (I think it might have been higher before, but I have been leaving a fan on in there for the past week)

Buds are 9" away from the hood

 

bump for update

I flushed with pH adjusted RO water, and set nutes back to ~930. Plants look about the same, maybe even alittle worse... any thoughts??

 

Thanks for the input, interestingly enough lately I HAVE noticed that my day/night temps have been very similar to each other (because for a while I was forgetting to turn off my a/c during lights off, which dropped temps down to low 60s), although I thought I was fixing a problem not creating one XD XD

I think I'm stuck in the same situation as you brah.... I'm kinda in limbo, I can't tell if I should be bumping my res back to standard PPMs, or give it less... or maybe even flush again.

 

I have cal mag on hand from my last grow, I'll try adding a bit of it to my nutes.

I'm a little disappointed though, I thought Micro in the Lucas formula had enough MG for proper plant growth...

 

I'm aware of color loss during flowering. But this is above and beyond that sort of yellowing don't you think? Also I thought that 'flowering yellowing' was only during the last few weeks of flowering, not the whole thing?

 

update/bump.... I think things are better after the flush. I still have yellowing, but the buds themselves are still developing fine and adding weight, so I guess they're okay lol. They do smell pretty damn nice.