I do 200PPM for starting into veg after the seeds/clones establish. When signs of being hungry start, I bump to 400PPM, then to 700PPM, then 900+ PPM depending on what the plants tell me. I go by how the plants look and not by a time schedule.
I move up slowly as being hungry is easier to fix than nute burn.
I think your way high and the plants are burning. Flush with zero nutes for a few days then start low and work up from there.
There isn't really a one schedule fits all.
Since the aerogarden is hydro, I would PH 5.5-5.8 to avoid nute lock out.