Epokwananswered grow question 5 years ago I don't have experience with growing indoors, but to me it looks like you might be getting too much moisture building up in those domes/bottles of yours. Even outdoors, I experienced some white spotting on some seedlings that were kept under bottles in the seedling stage. At the time, a fellow grower mentioned to me that white discoloration could be from light burn and I'm wondering if it could be that the pooled moisture on your leaves is magnifying the light and causing some weird kind of exposure to the young leaves.
Maybe try use bigger bottles and make sure there's enough airflow, so that they don't get too damp? It looks like you might have 2 issues there, the second could be the manure in your soil mix. Manure can be quite "hot", especially for young plants, possibly too much nitrogen or something in there. You might need to switch out the medium for something more inert. I'm sure they'll come right, just tread lightly with nutrients until they are more stable - sometimes less is more. All the best!