I would tend to agree with you about the 54 degrees thing. Anything below 70 will cause pepper seedlings to have stunted growth & they will never be the same again. I tried putting mine out in a cold frame when temps were getting high enough last year. A little bit of cold destroyed every single one of them. Could also be a fungus though. Pinch off the bad leaves, get them warmer & give them a few days to see what happens. - Steve

Undoubtedly the organic potting soil contained herbicide residue of some sort, probably something from the picolinic acid (aka pyridine-2-carboxylic acid) group. Herbicides from this group tend to include one or more of these active ingredients: picloram, aminopyralid, aminocyclopyrachlor or clopyralid. These herbicides generally are sprayed on grain crops to kill broadleaf weeds. Unfortunately the herbicide residue can survive the digestive tract of animals that eat the grains and the herbicides can survive composting. This problem is referred to as herbicide carryover and a common nickname for it is killer compost. It has been a persistent (no pun intended) problem since around 2000, when it popped up in both Pennsylvania and Washington State. Herbicide carryover damages and kills many gardens every year. Herbicide carryover even has been found in commercially-sold bagged organic composted manure products. When the state agency in that case tried to work backwards to determine how the composted manure became contaminated, they learned that the horses who supplied the manure had been fed a famous-name bagged horse feed containing ingredients apparently grown with one of those persistent herbicides. As far as I know, that was the first case where commercially bagged animal feed was contaminated with the herbicide. It is much more common for hay to be contaminated since those herbicides are sprayed on hay and other grain fields. So, am I surprised this happened to you? Nope, it happens, and it does not get a lot of media attention. If you are sure that your potting soil was herbicide-contaminated, you should contact the manufacturer and let them know. If there is a batch number or other identifying info on the bag, you might want to let them know. Here's more on herbicide carryover from the U. S. Composting Council: Persistent Herbicide

Too small to come out of the bag, and since they're no longer subject to high humidity, but are subject to high light/warmth, they're reddening up. You might want to water more often. There's nothing intrinsically wrong, though.

Thank you for the help. How concerned should I be? How can I fix the problem and repel those beetles?