Sure, np I run two different types of hydroponics and I have seen some sickly plants in my systems before, (RDWC and an aerogarden ultra
). The first thing I always check is my rez. If they rez has a bad smell, any white slime or brown sludge you need to change, I change my rez once a week at least. Hydrozyme and H2O2 are great to use in these system to help prevent/cure slime. You can also use aquashield. In my opinion a plant the size of yours should have nutrients at a low PPM between 300-500ppm of a primary grow nutrient. Increase dosage as plant gets larger and if it shows signs of aggressive feeding.