Thanks for sharing! Checking out the links from your profile, cool stuff. Relevant to where I live in Wisconsin, far inland from fresh seafood and in a similar climate zone. With YouTube's auto-translation, I can even understand much of what is said in Swedish in the Johannas farm videos.

One question about this video— at 1:46 the speaker says, "fish provide all the nutrients [for] our vegetables, which means we don't have to add anything artificial." Is this accurate? My impression was that aquaponics mitigates but does not completely eliminate the need for industrial fertilizers/nutrient solution additives, in addition to replacing what's removed when fish or vegetables are eaten:

https://www.youtube.com/watch?v=oGmJETrqzN4&t=1m46s

Another question— with aquaponics, how do you incorporate food waste into the circularity? Do you feed it to the fish, extract nutrients via an external physical/chemical process, or just dump it in the water reservoir and let it decompose?

With a nutrient recovery system, bioreactors, for the fish sludge, we think that we can get close to not having any supplemental nutrients for the plants. It depends on the content of the fish feed, the groundwater used etc. Exactly how close to zero time will tell, we are seeing great potential. The key is that the nutrients need to exist in the system in the first place and when you harvest something, you take things out. How do you put what is needed back?

We see that a very large portion can be done with circular biological systems. We have been working to incorporate food waste via insects. We take allowed food waste and feed insect larvae. There are several teams in Sweden working on this together, with some government support.

I haven't seen the "fermented plant juice" before, but the principle is the same, let bacteria work on it.