Mg Defic? or what?

what do you guys think is wrong with this plant and what should i do to correct it?

Nute burn..you feeding? Best guess.

nope thats the weird thing that i couldnt figure out... its in Pro Mix HP soil plain distilled water 6.5 ph. and the leaves are pure yellow

store bought water i got those on one of my plants too it look like this

I got one like that. I ve never figured it out. I wonder if they happen to get a hot spot in the soil. My runt still looks like shit and all its buddies look great.
Distilled water has no cal or mg or micronutes but I don't use it.

yea i use tap water but let it sit out for a bit it works great no nute lock out

try switchn to a diff starter soil could b too much shit in the soil for lil seed from the start try light warrior ff works ok

Soil channel hot spot.

The spots you can fix it if you add cal mag. If you are using distilled water you have to add a cal mag supplement no matter what. I'm not sure about the yellow. When I learned my lesson about distilled water and cal mag being necessary from the get go I still had a nice green tone to the leaves. Though if I were to guess I would think it might be PH related. distilled water doesn't give accurate PH readings with a meter. After adding a cal mag supp you can get a true reading. Also i seem to remember that pro mix hp has alot of peat which has high acidity on its own.