My advice, as a new grower that experienced a lot of problems, amplified by me trying to go extreme all the time....
1, do not ever use rockwool in your setup. It is asking for trouble.
2, if you don't have a chiller get one. I ran without one with good results but it is such a good preventative measure for bad shit growing in there, in the long run you will be grateful
3, the bigger the res the better. You may use more food but in the end everything is so much more stable and less maintenance.
4, invest in the best air pump you can. The more bubbles in there the better and faster your plant will grow. Some people rather use waterfalls and they do work, but I think bubbles are better personally and waterfall and bubbles are better! regardless! if you waterfall do it right and make it spray that shit all over the place.
5. good flow everywhere. I keep running into that issue, so do everything you can to make sure water moves freely around in there.
Other than that I feel like it is pretty straight forward if you keep up with your water changes and make sure your PH is right and stuff.
On a side note, I am looking at your buckets and I am curious, is that a DIY setup or purchased? it looks purchased. it recirculate? Do you have a link or a name for it because I really like it and I am considering replacing my buckets and don't want to DIY if I can avoid it.