Calling Dr. Weed

This a month old sativa. Some clusters show these spots, others don't, about 30% seem affected. The collective wisdom so far is a nutrient shortage.
I've upped the MG to about 1/2 strength and doubled waterings.
Any thoughts or spells appreciated.

Wow, only 1 month old? That's a shitty looking leaf.

I'd say more than just mag deficiency. The doctor will need to do a full checkup.

Bend over and spread em.

We need to know her vitals, what's she growing in, and how big. How much water and food. What's the air temp, ventilation. How much light and how close, etc.

Just like dropping the soap in the shower.

There's always time for lubrication!
OK, here's the stats. Garden soil. Her sister is in the same stuff, no problems with her. PH 6.9. Soil temp 78 degrees. I had been feeding 1/4 strenght MG general purpose every third watering, watering when dry. 2 gallon pots, good drainage. Not all the leaves look like that, I'll post a full pic. The total height is about 6 inches now. I've got three 23 W cfls about an inch off the leaves. The plant is very robust in general. There must be something with the soil mix, I'm guessing, since sis is doing just fine.
Better use three fingers.
Thanks in advance.
Merry Christmas. Smoke a tree.

Thanks for the details. Just a couple things, first, too much food. Young plants in good soil don't need ferts for at least a month. But you don't have good soil, so who knows? pH is a little high, but nothing to worry about. The temp could be, tho. 78 degrees for the root zone seems hot to me. If a hydro res is that warm, bad stuff happens.

Are the damaged leaves the ones closest to the CFLs?

Hmmm. I think they have been close to light when smaller. I try to keep the lights 1" away---maybe the damage doesn't show up right away? Also only some of the leaves are affected--maybe they were far enough away.
The plant is actually robust--she's just reaching for the lights.
I'm going to move them around.
Nice eyes, roast. Is that sleigh bells I hear?