Leaves turning brown from center out

I would agree with everyone that it looks like a cal-mag issue. It could be either a deficiency in cal-mag or the pH is off and the girls are not absorbing it the way they should.

Possibly from a need for calmag earlier on in the grow.

Or it could be a nutrient burn if not a deficiency… Your baby can not handle it’s nutrient schedule… Have you fertilized lately? Try holding up on fertilizer right now… you may have over fertilized. It’s hard to find a perfect amount of fertilizer.

Hey buddy! Cool looking shape of the plant I like how it’s like a perfect round bush lol - For your your problem, it looks like a magnesium deficiency on your leaves. But it’s difficult to determine without your nutrient feeding schedule attached to your diaries we can’t know what you’re doing wrong. As the plant grows into different stages (Germination, Veg, Flower) they all require different ratios of nutrients. You may need to adjust your ratios! Update your diaries for a better diagnosis! I hope this helps my friend! Good luck on your babies they look awesome