Potential Potassium deficiency? Brown

[growmbd2]

Looks to be a lockout from nitrogen. Having too much nitrogen ends up locking P and K from my experience. Go easier on the nitrogen levels next run bro. If you flush, it will cause different symptoms for sure. Once you end up with a lockout, the plant will never return to normal. This is why I go with coco, because you can feed to run off every time and prevent lockouts or fix them easier

That is pretty much inline with the advice i got - next time i will be using less nitrogen based feed