I came across another nice thing to combine with an aquaponic system:
black soldier fly farming. Especially in low density systems (with
fish way below the maximum stocking rate, mainly for safety reasons,
or where fish is not part of the diet) it is great, I have been told.
The 'tea' is highly nutrien rich, and can be directly added to the
water (after it leaves the fish tank), with great results. The mature
lavae are a high protein high calcium fish food.