So I've been running a chop and flip ibc aquaponics bed in my greenhouse for the last two years. The first few months everything in it looked nutrient deficient. It was probably about 6 months into it when I added a bunch more fish when the plants started to take off.
What can you do? Muck it up, over feed the fish, take any carbon out of your filter, etc. Your plants are your filter and if they are hungry you aren't at capacity. Go gradual, up a bit each feeding every day until you see the plants respond.
Or pee in your res.