Multiple plants same leaf issue

[Northbar]

Good afternoon everyone. The pictures are all different plants in the same tent. All are 3 weeks old.
Light- HLG 320
Soil - roots organic
Nutes - mega crop

Somewhere during week 2 I realized I had my light too low and raised it to about 30”.

All are getting fed MC at 2 grams per gal as of last week.
Sweet candy 1gram per gal
Sea kelp 1gram per gal

It appears to me that it may be a magnesium def. My last feed was yesterday to which I did add greenleaf cal-mag at a low dose, only cause I wasn't 100% sure if this was the issue.

I have several outdoor plants currently that were raised the same way earlier this spring and around 3wks were placed outside with zero issues. So I’m a little confused if the roughly 1week of too much light caused this or if somehow I ran into a mag def.

 

[Hrenklin]

Check you ph levels.

 

[The Celt]

I am no hydro expert but am using Mega Crop on some outdoor girls.

I believe if I am not mistaken, that Sweet Candy is a K supplement intended for the bloom stage. As these are young plants, and because MC is a K rich feed to begin with, my guess is you’ve overloaded the soil with K and this will cause Cal/Mag issues.

To fix this without chasing your tail in circles, flush your pots with clear water, 2 gallons of water for every gallon of soil, and then feed them again with JUST the MC and no Sweet Candy.

 

[The Celt]

Just went to MC’s site and the Kelp is a K source as well, pretty much guaranteed you have way too much K, especially for 3 week old plants.

 

[Northbar]

Check you ph levels.

I get my free water from a spring fountain and always 6.8. I feed my outside gals the same water. With all the nutes mixed it sits around 6.0

 

[Hrenklin]

I get my free water from a spring fountain and always 6.8. I feed my outside gals the same water. With all the nutes mixed it sits around 6.0

For soil its a tad on the low end. Ideally 6.2 is the lowest point for cal/mag

 

[Northbar]

Just went to MC’s site and the Kelp is a K source as well, pretty much guaranteed you have way too much K, especially for 3 week old plants.

Weird cause my previous run was done identical with no issues. I’ll drop the additional nutes and feed with just MC until they become more established.

Also, I have 9 total in the tent that I plan to flower at the end of wk 4. The ones pictured are the worst looking of the bunch

 

[Northbar]

For soil its a tad on the low end. Ideally 6.2 is the lowest point for cal/mag

Would I want to PH-up slightly To around 6.5ish after the nutes are mixed?

 

[Hrenklin]

Would I want to PH-up slightly To around 6.5ish after the nutes are mixed?

The ideal for soil is 6.2-6.5. I would only concern to have my range between that. I personally use coco coir so im happy between 5.5-5.8. I mix to 5.5 then let my feed stabilize for 1h and adjust into the range

 

[Northbar]

The ideal for soil is 6.2-6.5. I would only concern to have my range between that. I personally use coco coir so im happy between 5.5-5.8. I mix to 5.5 then let my feed stabilize for 1h and adjust into the range

I mixed a fresh batch with JUST MC and steady sitting at 6.5 with no adjustment. I’ll monitor my PH more closely. Thanks for the help.