That's an ambitious endeavor ... 200 plants. Regardless of what you do, it's going to be a lot of work.I added a little bit of perlite, but not at all a lot. To transplant would b a lot of work. small room. allmost 200 plants
Consider flushing your plants with distilled or filtered water and then immediately follow up with a feeding at half the strength that you were. This might be enough to reset things.