Can anyone help identify this?

[PdxMatos]

I started some seedlings a month ago and they were coming up fine in their plugs, but soon after I transplanted them into pots, they started having all sorts of trouble. Leaves drooping and turning purple. (Photos 1 and 2) Leaves not quite growing right, and yellowing and curling up at the edges. (Photos 3 and 4) and some plants becoming badly deformed, so much that I gave up and pulled them up. (Photos 5 and 6)

The soil seems in the 'green zone' according to my moisture gauge. There should be plenty of nutrients. They are indoors under a grow light, so their temperature and humidity is fairly consistent. There are a few insects flying about, but it doesn't look like insect damage, and it is affecting many varieties (albeit in quite different ways) some of which are fairly disease resistant. In fact the worst affected seem to be BigBeef and Maxifort which are resistant to most things.

Did I do something wrong?