So... This is more comparable to a guppy tank than a farm.

Generally, yes you are right. Home farming (eg vegetable gardening) generally isn't economical. That doesn't mean it's not valuable. Besides being fun... I do think home gardening some resilience to the food system.

Aquaponics is, in general, not really a viable commercial method. Or rather, the plants are just a filter for the pinds...not a true secondary product.

Still... aquaponics is fun.