Browning edges and slow growth (lots of pics)

These have been in veg for over a month. Recently repotted from Dixie cups, growth seems to be very slow, maybe stunted and some of the edges look like they're burning.

I was giving them nutes in the dixie cup and they were doing fine, but have not given them any nutes since repotting a week ago.

(600w MH, ~85F, 50% humidity, maybe a little less due to the heat)

Please help!

(edit: According to my state's site, pH of water is ~7. I leave it out for a week so the Cl evaporates, but it's definitely hard water)

I've had this happen many times before, it usually happens when nutrients buildup in one area and become toxic. That's why it's only one or two leaves, it's a small patch of the stuff with the roots tapping it.
Only way to fix it is to flush the pot with about twice the amount of water the pot holds. even that sometimes doesn't push it all out, and you'll need to do it again. It really sucks, cause sometimes it spreads to other roots making the leaves alittle yellow.
Looking at your leaf tips, you might be overfeeding your plant more nutes then it wants.

flush 'em! when your plants (at that age) look almost too green, (you'll recognize it, now!), time to stop giving it goodies (ferts and nutes) it has been fed too much. Stop, and water it about 3x what you normally would (until water runs freely out your drainholes) wait 5 minutes, and flush again. Hopefully this will have gotten rid of most of the toxins (nute buildups) that it was given

By 'too green' do you mean that bright green on top of the plants?

I was thinking it might be nute burn but the thing is that I haven't fed them any nutes since transplanting, and my other plants (not pot) repotted just fine (I also didn't give them nutes) so I don't think the soil has excess nutes.

Could it be pH lockout? I'm not checking pH, and tap water here is ~7...

I'll flush the soil anyhow, thanks.