So I’m growing in a tent with ffof. I water with tap water baked In the sun for a day. I’m using led lights. This is my first autogrow. Well practically my first grow period. I’m starting to notice some rust colored marks appear on 2 of my fan matured fan leaves. I’m about 35 days since the seed sprouted. Anyone have any thoughts? Maybe start putting some calmag into the water? I have some dolomite lime I could use as well. PleAse let me know what your thoughts are thanks!
It's hard to help you diagnose your plants with those LED lights on. If you can take the same pics in natural light it would help.
Looks like it may be calcium deficiency. @trojangrower was right, add more calcium on your next feeding.