Just a quick update. My three sweetcorn plants are over two feet now, and no signs of browning, but some signs of nutrient issues. The system is a bit new, and there are a bunch of tomatoes that may be stealing the trace elements. Just topped up on Trelmix today and we will see how the corn responds
Sometimes systems can be very persistant about pH. Mine flatlines on 6.5 and there are about 2 cupfulls of lime and multiple additions of potassium hydroxide having been added and still no shift (Whole system water volume only about 1200 - 1500 liters). Anyways, it seams to be alright for the plants in my system.