Week 6 of flower - Need help ID'ing my issue - Could either be low pH or light burn but not sure.

[Crumbuds]

Hi Everyone, Thanks for looking at my post.

First grow - Week 6 of flower . (Bruce Bangers and White Widow - both Fems)

Ive got issues that I think (in my limited experience) could either be light burn or low ph. everything else in the room is pretty spot on, temp, humidity and airflow.
Needing some experience from the community to advise if possible.

I'm starting to get some discolouration a week ago - it's getting worse. (photos attached).

Situation: I've got a 50/50 coco and organic soil grow (wanted to test what worked better for me so I tried a few pots of each) . Watering with 5.5ph water (this could be my problem) or it could be distance from light. I let my girls veg a bit long due to grow room build delays. They got a little big before flipping. Growth has levelled out and they're pretty close to the light. Closer than I'd like.

I am starting to up the ph of the water to 6.5 using ph UP. Lights I can't do much more than I have as they're near the roof but they seem to have stopped stretching.

what's weird is some plants are absolutely perfect , whilst the one next to it is showing symptoms. Happening on both coco and soil. So it isn't a 'media' issue I dont think.

Watering once a day. Following the instructions on the bottle for the coco. Soil gets an organic bloom mix once a week and not too strong.

Thank you in advance, your help is really appreciated. Im so close to harvest. I wanna keep them on the rails till they graduate!

Thanks

 

[ApolloCanna]

Looks like a deficency to me! But being this close to harvest i dont think its too big of a deal. Its normal for leaves to yellow toward the end of growth!

 

[Aqua Man]

Calcium deficiency. Your PH is to low and its locking calcium out. Try feeding foliar and adjust your PH. It may be a good time to flush and feed but wait for some Coco growers to pop in as i'm seeing some other signs of deficiency also.

 

[QuestForZest]

Calcium deficiency. Your PH is to low and its locking calcium out. Try feeding foliar and adjust your PH. It may be a good time to flush and feed but wait for some Coco growers to pop in as i'm seeing some other signs of deficiency also.

100% agreed (Ca deficiency) but also be careful of foliars so late into flower as you do not want any mold/Bud rot issues.

 

[Aqua Man]

100% agreed (Ca deficiency) but also be careful of foliars so late into flower as you do not want any mold/Bud rot issues.

good point

 

[Jimster]

a DOSE OF cAL-mAG APPLIED FOLIAR SHOULD HELP MATTERS QUICKLY, BUT AS OTHERS HAVE MENTIONED, BE CAREFUL NOT TO oversaturate stuff or let your humidity get too high as mold and mildew can strike quickly in the bigger/thicker buds.Not too strong so that you avoid possible burning. Sorry for the caps in the 1st part of the post.

 

[jumpincactus]

Looks like C defish sort of looks like this classic pic of it.

 

[MIMedGrower]

Yeah definitely advanced calcium deficiency i think caused by too much pk.

When upper leaves burn or stress its time to leach pots with fresh water and if needed feed a lower dose of complete balanced nutes. Bloom nutes are not supposed to be used as the only fertilizer. They are mostly what yellows plants prematurely in flower.

I would flush with fresh water until i saw clearish runoff that shows 6-7 ph and maybe 1.2 ec max (600ppm). If it eneded up lower i would run a light nutrient dose through after.

 

[Crumbuds]

Thank you everyone - I am going to get some cal mag and get on to it asap. I really appreciate all your advice and will come back with an update shortly. I will try light foliar spray on the lower leaves too to get it in to the plant , just before lights out.

 

[MIMedGrower]

Thank you everyone - I am going to get some cal mag and get on to it asap. I really appreciate all your advice and will come back with an update shortly. I will try light foliar spray on the lower leaves too to get it in to the plant , just before lights out.

I am going to guess spraying cal mag wont help and will likely mess up the flowers. Dont spray when flowering.

First course of actuon is always leach pots with fresh water to clean out the roots of built up nutes and waste.

Without a good measure of the runoff no advice given is credible. You have to see what the problem is first.