Duckweeds are among the fastest growing higher plants, edible and rich in protein. They grow in lakes that are rich in nutrients, for example from fertilizer runoff. They have been used as tests for water contamination or for the treatment of certain industrial wastewaters. Now, I wonder if one could raise duckweed at home, using wastes or wastewater as fertilizer.
Suitable wastewater sources could be water from dishwashing, compost tea or possibly even urine. Wastes might be kitchen scraps, coffee grounds or the like.
When using waste water, most relevant parameters for contamination can be expected to decrease. Still, I'm right now not focusing on generating clean water but on food production.
While there are some experiences with raising duckweed for feeding fish or turtles, the ones I found all use bought fertilizer or even fish food - no wastes.
I think the following questions should be answered by a success story:
- when wastewater was used, any special consideration regarding cleaning agents/detergents?
- when kitchen wastes where used, what kind, what treatment
- Was there any problem with odour or modges or other pests
- was there any need for micronutrients
