Royal queen seeds purple punch auto

So I had some nutrient burn I have been keeping the ppm around 200 but fed a day early and the following morning both had brown spots on all older growth. So I flushed and changed the water in the aerogarden resovoir. Then after some thought I decided to no longer feed in the aerogarden resovoir directly and try an IV approach using the aerovoir extra resovoir to house the nutrient solution already diluted by gallon. Then I measured the water in the aerogarden and it was 130ppm. My well water is 96ppm with nothing added. So after pruning the brown leaves and rearranged the large leaves under new leaves to get light down there and I think it will be a better start to week four