Deficiencies under 20 days old?

I’ve got a wickedpissah black cherry pebbles in a 3 gallons of soil under a 135 watt GB. Temperature 75 degrees humidity 65 which seems ideal. Yet it looks almost like a calcium deficiency even though it’s still young. I’ve never had a deficiency this early, is it calcium? I’ve heard using led can cause calcium issues. Any thoughts?

Overwatering?

I don't see signs of a Ca deficiency, in fact, the plants look good. I do see some necrosis on the lowest leaves, but the picture isn't clear enough to decipher whether it's a problem or not.

The issue is we have no idea what you are feeding them, how much? how often?