DWC Auto AK XXL

Busy Week.. At beginning i was facing lower leaves that didnt really look good so i removed them and started to add CalMag. At the same time i was experiencing this brown gunk in my roots and opened a question. While my water has not the best temps for DWC i am using H2O2. Using Master Root from Xpert Nutrients at max recommended solution (2ml/L) which contains living microbes wasnt the best thing to do. I got in contact with couple of guys replying to my question which made me change couple of things: First, i am going sterile from now on, so no living microbes at all while using H2O2. Second, i checked the ideal hanging height for my light which turns out to be around 25-35cm Third, raising the DLI to around 30-32 I washed away as much gunk from the roots as possible. Some brownish stains stayed, though. Smell is good, no rot as far as i can tell. Cleaned the res and used not Master Root at all, only Grow A+B and CalMag amino from Xpert Nutrients. Plant looked a lot better the next day already