My tomato seedlings are about a month old, I repotted them about a week ago and some are developing what looks like bubbles on the leaves. As the time goes on the bubbles turn yellow and so does the leaf. Everything I used was sterile and the plants are inside under grow lights so disease shouldn’t be a problem. Also some of the leaves are curling. I water so the plants are never soaking wet but never bone dry. I also used half strength fish fertilizer about every other watering. So I am stumped on what is going on with the plants.