I think this is a great idea.
I grow a lot of veggies in a similar but larger system using a fish tank as the nutrient source. The tank water is pumped through the growing medium which acts as the biofilter. The nitrification byproducts are then taken up by the plants as their nutrient source. It’s a complete system, and the only inputs are fish food and water to compensate for evaporation and plant transpiration. The occasional micro-dose of seasol (seaweed based liquid fertilizer) also helps to top up trace elements.
check out www.backyardaquaponics.com
I remembered that! Thanks for posting. :)