Light Stress or Iron/Cal/Mag deficiency??

[Ichibaniles81]

Please Help! After moving the new light in a few days ago my plants have shown very bright-green new growth. Question is, do you think it's light stress or iron deficiency etc.? They are 10 days into flower. Coco soil mix in 4-5 gal pots, recently defoliated and Lst. Approx 18 inches from light today although I shifted lights up just then so looking at 20 inches away now. I've begun using K and reduced N but haven't given much trace elements for over a week so I just hit them with that. Also they get homemade Cal Mag once per week. Thanks!

 

[Gjohnstone]

Just looks like new growth to me, it can come up lighter at first. Plants look great, I would not worry. Cal/mag def would come up spotted and brown looking.

 

[9fingerleafs]

yes very true, specially during the switch stretch, the plant grows too fast to fill the leaves with nutrients, usually a few days later they get darker, only the newest are yellow. if it makes you feel more comfortable you can mark one yellow leave (piece of take or smtng) and check for improvement every few hours, youll see nothing to worry about

 

[Ichibaniles81]

Thanks for the vote of confidence. I'm about to check on them again so we'll see. I gave them a small amount of Cal Mag which they were due for anyway. Plus I moved the light up and also switched the 300w light off for yesterday's 12 ON.
I'll post a photo in a sec.
One thing that occurred to me after posting, these plants did something similar JUST before I potted up and as it turned out they were root bound. They rebounded about a week after they were re-potted. What the heck would I do if they outgrew 5 gal pots?? The tent hardly fits them as it is!

 

[Ichibaniles81]

Okay, there seems to be a very slight improvement so that's a good sign. Especially considering it's only been 24hrs or so. I'll leave the second 300w off for a couple of days until it settles and Re start but only with bloom lights and hope for the best. Otherwise it's back out with the 450w And back to 2x 300w.
will update progress

 

[Rwise]

5 gallon should be good for an auto, for photos I would go 15+G and use cloth pots. If you have hard pots (plastic) one can drill them full of holes so they breath. This will stop them from becoming root bound as the outside layer dries and the roots self prune.. I went to cloth pots last year and luv them!

 

[Ichibaniles81]

Thanks Rwise, so are you saying I can still drill a bunch of extra holes around the sides and it will help? That would be really good to know because I am kind of worried that these roots are pretty much filling out the pots, but I definitely don’t have any more floor space. In fact, I was considering using two of these 5 plants for cuttings and starting a SoG in my Veg tent with 12 cuttings for the next grow. Smaller pots but quicker cycle so they all fit. So many options.

 

[Ichibaniles81]

So just an update, I did take out the 450w, and with it I took 2 trees and had them running in 2 separate tents for 2 weeks. Recently I defoliate all 5 plants and put them back in together, but this time with the 2x 300w only. They are 5 weeks into flower and seem to have settled. I do believe it was a light issue from disrupting them mid-grow by changing lights and wattage. Here are some updates photos..
as you can see on the close up, there is some residual issues and I have got “rust spots” and burnt tips. I pH the water and have given notes but can’t win all the time..