Backyard Fowl Keepers

I have a septic lagoon covered in duckweed, which I know is a great protein source. I've heard the top layer of water in a septic lagoon is relatively clean, but Im unsure if the duckweed is safe to feed to animals. My lagoon only receives overflow from a septic tank, and with just two people in the household, overflow is rare.

Would the duckweed be safe to use, or should I avoid it? Does having a septic tank before the lagoon make a difference? Looking for advice!

The safety of using septic lagoon duckweed depends on what's in your household waste. If you use strong cleaning chemicals, pharmaceuticals, or antibacterial soaps, those can end up in the lagoon and be absorbed by the duckweed. Even if the water looks clean, you can't see bacteria or chemical contamination. If you want to be extra cautious, you could try growing duckweed separately in a small container and compare it to your lagoon's duckweed for differences in growth and appearance.

If you want to use duckweed, consider growing some separately in a clean pond or tub. Lagoon-sourced duckweed carries too many unknowns.

PhoebePeep wrote: Tue Feb 18, 2025 12:24 am I have a septic lagoon covered in duckweed, which I know is a great protein source. I've heard the top layer of water in a septic lagoon is relatively clean, but Im unsure if the duckweed is safe to feed to animals. My lagoon only receives overflow from a septic tank, and with just two people in the household, overflow is rare.

Would the duckweed be safe to use, or should I avoid it? Does having a septic tank before the lagoon make a difference? Looking for advice!

While it's true that septic lagoons settle out solids and can have relatively "clean" upper layers, that doesn't mean the plants growing in them are safe. Duckweed absorbs nutrients and contaminants from the water. Even if pathogens don't directly harm the plant, they could be present on its surface. Additionally, heavy metals and chemical residues from household products could accumulate in the duckweed. If you're thinking long-term, setting up a separate tank or pond for growing duckweed would be a much safer and more sustainable choice.

PhoebePeep wrote: Tue Feb 18, 2025 12:24 am I have a septic lagoon covered in duckweed, which I know is a great protein source. I've heard the top layer of water in a septic lagoon is relatively clean, but Im unsure if the duckweed is safe to feed to animals. My lagoon only receives overflow from a septic tank, and with just two people in the household, overflow is rare.

Would the duckweed be safe to use, or should I avoid it? Does having a septic tank before the lagoon make a difference? Looking for advice!

It's true that the top layer of a septic lagoon is clearer, but that doesn't mean it's free of bacteria, parasites, or harmful chemicals. Even if the septic tank filters solids, the lagoon may still contain harmful pathogens, nitrogen compounds, or pharmaceuticals from household waste. Duckweed is known for absorbing contaminants, which is why it's great for cleaning water but not ideal for consumption in this case. If you want to use duckweed as feed, it would be safer to grow it in a controlled environment like a small pond or tank.

Some farmers use wastewater duckweed as livestock feed, but they typically test the water quality first. If you really want to use it, consider testing for contaminants.

Duckweed itself is highly nutritious and used in animal feed worldwide, but where it grows matters. Septic lagoons contain not just waste but also potential pathogens, pharmaceuticals, and household chemicals. The fact that your lagoon only receives overflow helps, but it doesn't guarantee safety. If you're set on using it, consider testing the water for contaminants first, but growing duckweed separately might be a better option.

I'd avoid feeding duckweed from a septic lagoon. Even if the water looks clean, it can contain harmful bacteria or contaminants that could affect your animals.

Septic lagoons can contain pathogens, even if they look clean. The duckweed could absorb harmful substances,personally, I wouldn't risk it.

PhoebePeep wrote: Tue Feb 18, 2025 12:24 am I have a septic lagoon covered in duckweed, which I know is a great protein source. I've heard the top layer of water in a septic lagoon is relatively clean, but Im unsure if the duckweed is safe to feed to animals. My lagoon only receives overflow from a septic tank, and with just two people in the household, overflow is rare.

Would the duckweed be safe to use, or should I avoid it? Does having a septic tank before the lagoon make a difference? Looking for advice!

Duckweed is fantastic for poultry, but lagoon-sourced duckweed is a gamble. If you use any cleaning chemicals or medications in your home, they could end up in the water and get absorbed.