Do i have Mag deficiency? Advice please :)

so here be the pics:





So only just noticed this today - pretty sure this was not present yesterday.

It's on 2 of my 4 so far.

These are 8 ball kush in canna coco, under chinese leds, in large-ish pots (15-18l) and are being fed formulex and shogun cal-mag - per litre dose at last feed was 6ml formulex and 1.5ml cal mag. Due to nights away etc they have not got as dry as they should before next feed. This feed level is typical for me over the past 2 weeks. Last feed was friday.

They are six weeks from popping the seed in the media, temps range from @62-70f, rh about 45%

What i was thinking of doing is just letting them dry out a bit and then flushing, then back to regular feeding once they are thirsty again after the flush.

Have i overdone the cal-mag and locked out the Mg as it fights the cal (or am i just cunfusticated?) or is there another issue from what folks can tell?

Cheers in advance lovely peoples!

Anyway to get pictures of the whole plants friend?

sure, will post more as soon as..

Yes that is as i am going to thc univeristy and cal/mag was are first lesson the red middle veins are your first sigan so cal/mag add a lil and she well be good in no time

So if it is Mg deficient here are my thoughts/concerns - bottle's stated dose (shogun cal-mag) is 1 ml /litre on hand feed like i'm doing, and i've been on 1.5ml a litre, cos coco (or so i read etc) - am i right that cal can lock out mg?

if so, should i dose with epsom instead to prevent lock out and a cal overdose, or should it be ok to say up the cal mg to an entirely arbitrary 2.5ml/litre for example?

cheers in advance all

if it's any use, here is a thread of them from 1 week ago:

https://www.rollitup.org/t/my-very-own-crappy-ufo-grow.925980/

meh, can get link to work properly

Look into the application of Epsom salt either in feeding or foliar spray, 1Tbps per gallon. If it is Mag Def should clear up in a few days.

no probs, done it years back.. needed some folks to confirm what i thought before i did something stupid and royally screwed up! Cheers

This morning the discolouration had grown a bit.. so i dosed with epsom, and when i took them out of the room to ditch the run-off it was the first time i'd seen them in natural light for a few days (the photos were taken in the dark), the leaf discolouration/mag deficiency didn't look as advanced as it did under the blurple.

So blurple makes the brownish discolouration more noticeable, which is kinda useful.

Just for reference, i surmised (after various efforts to resolve) that there was possibly a little deficiency but that this was certainly also sunburn from the LEDS which have UV and IR bulbs.. you really need these lights about 10 inches or more from foliage - you can get away with a bit closer if you turn the plants etc to spread the "tan". Personally i'd turn them regardless.

Thats calcium not magnisum.