Sam Brown-Kenyon

Duckweed

Alternative food sources

As we investigate different food sources for our fish, duckweed emerges as a hassle free option.

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duckweed - small bucket Peter Gigg

Duckweed absorbs nutrients and forms a layer on top of the water, which quickly multiplies. This cleans the water and helps combat algae growth, while also providing a nutritious feed for animals and even humans. Duckweed prefers nutrient rich, still water and some sunlight. After collecting a small sample from a canal, we first started with a small bucket with water from out aquaponics system. Once the plant had covered the top layer of the bucket (around 1 week), we transferred this to a larger bucket to repeat the process. We will monitor the progress and aim to have a reasonable amount of duckweed before we start feed it to our fish.

Update: After covering the top of the water in the bucket below, the growth has slowed significantly and the duckweed has started to dis-colour. This is probably because the nutrients added to the water have been insufficient to maintain growth. Worm tea from the compost, as well as the liquid from the black soldier fly enclosure was added to provide nutrients. This has not provided the growth we desired and will now revert to water from the aquaponics fish tanks, which provided the initial satisfactory growth. More to come..