Backyard Aquaponics
A place to discuss aquaponics

Full article.

In the article they talk about human urine stimulating algae growth which in turn helps plankton growth. But how do you extract plankton and feed it to the fish?

Would it be possible to grow for instance Spirunella/Chlorella/whatever on diluted urine, for fish food? I know it could probably only be a diet supplement for the fish, but it's probably also easier to extract and grow than plankton. Maybe build a 'biocoil' much like this one as photobioreactor, so it's closed-system.

People produce about 1-1.5l of urine a day, containing 10-20g total nitrogen. Chlorella (just an example) can convert about a third to half of total nitrogen - say 5-10g - to biomass, and their total biomass is about 10% nitrogen, would that mean about 50-100g of algae growth a day if grown only on a person's urine?

It might help "closing the chain" with as little input as possible: person eats AP food and produces urine, urine feeds algae (possibly feeding plankton), feeding AP fish, which produce urine feeding AP veggies and then it starts all over again with the person eating AP fish and veggies.
It's not as complete a chain as with a vermicomposting toilet unit, but feces isn't sterile and you can't use compost in an AP system directly..

Alternatively, would peeing in a duckweed pond stimulate duckweed growth? Wouldn't be as productive per square meter as a PBR, but would certainly be cheaper and easier. I've read about people growing duckweed in ponds with chook poo chucked in, so I guess this'll work too?

Just thinking out loud!

No doubt you will gather some followers here mate!

Tilapia can get phytoplankton out of the water through their gill rakers.

it seems like a great idea, but i whouldnt go over board with pee pee. but the logic is there.

-df