Does this look like magnesium deficiency to you?

I have 2 auto plants on day 15 that look like they are starting to have a little yellowing between the veins on some of the leaves. Does this look like magnesium deficiency to you?




The details on it.

The plants are mephisto sour crack on day 15 in 50% soil 40% perlite 10% biochar in 3 gallon fabric pots on there.

I have the 240w kingbrite quantum board led 3500k with 660nm red on like 70% power at like 40" from the top of the plants in the tent with like 77 - 79f with 50 - 55% rh on there.

I water with tap water that I use ascorbic acid vitamin c powder to remove the chlorine or chloramine in it. I have done a few waterings with coconut water and 1 watering with aloe in it.

The nutrients are biotabs organic dry amendments with 2 biotabs per pot with startrex mycotrex and silicium flash in it. I follow the just add tap water guide from biotabs for it.

Do you think that is magnesium deficiency or what? I want to find out if people think it is magnesium as I would then plan to put some epsom salt in the water next time I water it for it on there.

Its definitely not magnesium because magnesium def starts from bottom to top, while yours look more like a iron lockup ?

Thanks.

Its caused from having too high of a pH. You have all the nutrients you need but the wrong pH.

Here's a simple chart for reference: