Babyblue: 99.5F is for a bator with a fan. In a still air bator the temp should be slightly higher, I think about 101F at the level of the top of the eggs. But you say your first chick hatched on day 19, which (unless they were bantams) would make most people think that your temps were actually too high, not too low. Maybe with it being still air you had hot and cold spots in your bator. Some people really don't like LGs but some people have great hatches with them, so don't be too quick to blame it all on the bator...
I'm sure other people will have more ideas about what could have gone wrong in there.
I'm sure other people will have more ideas about what could have gone wrong in there.