Curled leaves with purple underside, plus yellowing?

[hiker_]

First time starting from seed here folks...

All of my 2-week-old seedlings seem unhappy. I do the whole "pet them" thing and they are a little limper than before. Not like fainted or anything, just a little limper and drooping a little.

The occasional leaf is curled (up, not down), especially where they are touching each other. And the undersides of these leaves are turning purple. Again, it's especially the curled leaves. But it's also happening in many areas on the oldest seedling (different cultivar, came up a day before the others).

Yesterday I watered the oldest seedling with "Park Success," 20-20-20 for seedlings, and I mixed the "for small seedlings" amount (1/4 teaspoon per gallon). It seemed to perk up, so I thought I wasn't feeding them enough. I watered them all with it today. Not sure if they liked that or not. (Photos below.)

I started some peppers at the same time and treated them in basically the same way. Their leaves are pretty yellow, especially the new true leaves. That's another reason I thought the problem might be not enough fertilizer.

I've been worrying because every day when I check them they're still pretty wet, so I don't water them any more, so then they don't get any more fertilizer, but I also don't want them to be too wet...etc.

Or is the basement too cold for them? (I'm estimating it's about 65F.)

They're in "container mix" of "sphagnum peat, perlite, vermiculite and limestone"--no fertilizer in it. They're under two shop lights with one warm and one cool bulb each. You can see the bottom edge of the lights in the photos below.

This is the one that's worst affected. First photo day (and not a good photo, it's out of focus, but you can kinda see the curled leaf in the middle), second photo half an hour before the light goes off (and 6 hours after I fed them):

DaytimeCloseup.jpg
EveningCloseup.jpg

Tomatoes on the left, oldest tomato + peppers on the right (again, first photo day, second photo half an hour before the light goes off):

Daytime.jpg
Evening.jpg

They are just...drooping now in a way they didn't before. You can see it in the photos, how they are kind of..."swaybacked." I'm not talking about the leaning, I'm talking about the bends in the stems, as if they were having trouble holding themselves up. And again, they feel...softer than before.

Any thoughts on what I should do? Or should I just stop worrying already?