Is this Mg deficiency or something else?

[Markyb]

Hi! This is my second auto grow and she is now 4 weeks old. Otherwise she looks really healthy and I think she has grown very well so far.
But I have noticed weird light patches on many of the fanleaves. Could this already be Mg deficiency?

I have already dialed down the light in case it was receiving too much.

Im growing in Biobizz LightMix which does not have much nutrients in it but I have already started a light feed with Canna Terra Vega + CalMAg. EC=0.8 And to my eye the patches don't seem like N-defiency (but what do I know).
I have added Calmag because my tapwater is super soft (EC 0.1).
I always condition the water after adding nutrients, to Ph 6.8.

I have checked the Ph of the runoff every time and its always between Ph 6.4 - 6.6.

Also many leaves have thse weird "tags" on them, like a smaller leaf growing inside a leaf.

 

[Frankthetank]

The tags are just genetic….nothing to worry about.

I think she’s beginning to want a light dose of phosphorus with her feedings…. So you might think about switching to flower nutes….

That’s my opinion, anyway

 

[Dab]

Yeah it could be Mg but why too much Ca from the calmag maybe? The dark leaves make me think it's too much of something locking stuff out

 

[BII]

Yeah it could be Mg but why too much Ca from the calmag maybe? The dark leaves make me think it's too much of something locking stuff out

Don't look too dark to me, but dark leaves suggest excess N. Switching to bloom base nutrients which generally have reduced N could fix this(?).

 

[Dab]

Don't look too dark to me, but dark leaves suggest excess N. Switching to bloom base nutrients which generally have reduced N could fix this(?).

Yeah not really dark but dark on the edges in the close up now that you mention it I do see the N. Yeah probably just a switch to bloom will do the trick I'd cut the calmag too She looks pretty good really I wouldn't change much

 

[BII]

Also, I'd suggest foliar feeding including some epson salts (MgSO4). Some magnesium deficiency showing up in early bloom seems rather normal, and fixable. Check how much Mg is in your bloom booster(s) and base nutes, which could have higher Mg.

If not using, check out Transport from Optic Foliar, allowing foliar feeding by simply spraying the tops, not bottoms, of the leaves, and is more effective and doesn't require darkness or specific temperatures as the usual non-chemically-assisted bottom of leaf spraying foliar feeding often does.

 

[Markyb]

Thank you for all replies and help!

The spots have not spread since I posted the first pics, but they have not cleared either. I assume they are something that won't disappear even if the underlying problem might have been solved? Also she has been growing FAST, has pretty much doubled in size since I posted this topic.
I Have not added CalMag anymore in case it's some kind of a lockout. If I see the spots spearing again I'll try the epson salts, thanks for suggesting it!

Initially I started adding the CalMag only after I saw the first signs of those spots. (My tap water is super soft and base nutrients barely have Mg or Cal in them, the manufacturer actually recommends conditioning the water to EC 0.4 with CalMAg for their nutrients) The first spots actually appeared even before I started feeding her anything.

The runoff EC is relatively low when I water just plain water (runoff is 0.5). I understand that runoff EC in soil is a thing I should not rely on, but I have understood it's the delta that matters (its been going down 0.1 - 0.2 with every watering, I have assumed it means she is feeding at least at some rate?) and that even thea absolute runoff value could give some hints if the value is extreme in one way or another. Thats why I have been taking the reading even from the runoff.

I did feed her more generously with the veg nutrients because my last grow ended up with a severe N-deficiency at the very beginning of flower and it almost did not finish. (I was really stingy with the feeding with my last grow, but I have also tried to be carefull not to go overboard with this grow).

That being said, I have now switched to bloom nutrients as many of you suggested.

 

[Markyb]

Here she is now, in my opinion she has grown alot in just a few days. The leaves looks droopy because its almost lights-out time, she always does that just before bedtime

 

[Cannaficionado]

Here she is now, in my opinion she has grown alot in just a few days. The leaves looks droopy because its almost lights-out time, she always does that just before bedtime

View attachment 1775966

She's started flowering it looks like, she's gonna stretch, looking good though