Business at Amorgos

[Guillermo Block]

Been a while, some updates for my logbook:

Given circumstances on this planet a closed loop system is the only option. Only that way can we guarantee nothing is lost and the precious resources are fully used. One of such systems is called “aquaponics”. The idea is simple: feed fish, and they will produce litter. The litter is then turned into nutrients by beneficial bacteria. These nutrients are then extracted from the water by the plants. By doing so they grow. The clean water is cycled back to the fishes. This way no hydroponic solution (such as HydroGro by Samura) is needed.



Various configurations are possible, for example the nutrient rich water can be flown through tubes in which plants grow:



The plants can also be grown on polystyrene plates which float in a basin of water (so called floating raft).

Plants can create own hydrocarbons compounds through photosynthesis, but depend on external nitrogen, phosphates and minerals-sources. The required phosphates are approx 10-20x smaller than nitrates:



The original aquaponics system can be improved for our purpose through two ways. As the nitrates are introduced in the aquaponics system through fish-food it would be beneficiary to produce this ourselves. Readily made fishfood is somewhat expensive to buy:

- “Impact of rising feed ingredient prices on aquafeeds and aquaculture production”, http://www.fao.org/3/i1143e/i1143e.pdf [… in 2008, the price of fishmeal was US$1210 per tonne. ]

While prices of phosphate and nitrogen (in the form of urea) are nearly a factor 10 lower:



It might also be possible to completely cut out the necessity of urea using nitrogen fixing plants. We will investigate this later.

Secondly the produce is not completely eaten (e.g. leaves, straws), which is a nutrient rich resource in itself. We will use compostation to recycle this and reintroduce the nutrients back in the systems.


Our aquaponics system will be modified to the one above.

Compositing also forms a backup system: in the case the fish get sick we can still continue through compostation. Multiple processes are identified and will be explored/optimized:

1. Producing fish food
2. Feeding the fish
3. Convert fish NH4 to NO3
4. Growth of crop
5. Composting

But that's for next time.