Brown spots

This is a white widow at 3 weeks old that I just transplanted from a solo cup to a 1 gallon. I watered it good when I transplanted but 4 days later still looks like this. It looks overwatered but I don't see how. I transplanted it from happy frog to ocean forest and its in a smart pot. It started developing brown spots on leaves. What are your thoughts?

Prob calcium def, not sure cuz im not feeding it (lol) but if you are feeding it using FF products you might want to stop for a bit. Flush it well (as well as you can cuz it looks like your soil wont drain well) and then start a base line feeding regiment & go from there or just add Cal during next feed. And they are too young to be feeding heavy any way! So be easy

Also... its over watered for sure, from the looks of it your soil mixture needs a lot more perlite (or something to help drain)

Likely calcium deficit. Have you fed this plant at all? If not it is time to start. If you have, what did you feed? And she needs micros too.

I haven't fed the plant at all yet but I've been using distilled water so calcium deficiency makes sense since there's none in distilled water. I'll start feeding them with some calmag. Would you recommend using distilled water or aerated tap water?