Duckweed is one of the most controversial aquarium plants in the hobby. Some aquarists swear by it and refuse to run a tank without it, while others spend countless hours trying to remove every last piece.
So, is duckweed a miracle plant or a green nightmare? The truth is that it can be both.
What Is Duckweed?
Duckweed is a small floating aquatic plant that grows naturally on the surface of freshwater ponds, lakes and aquariums. Under the right conditions it can reproduce extremely quickly, covering the entire surface of a tank in a matter of weeks. Despite its reputation, duckweed provides several benefits that make it a favourite among shrimp keepers, fish breeders and planted tank enthusiasts.
Why Shrimp Keepers Love Duckweed
Natural Food Source
Duckweed develops a biofilm on its roots and leaves which provides a constant grazing area for shrimp. This biofilm contains microorganisms that shrimp love to feed on throughout the day.
Helps Maintain Water Quality
As duckweed grows, it absorbs excess nutrients from the water column, including nitrates. This can help reduce algae growth and improve overall water quality. Provides Shelter The hanging roots create a natural refuge for baby shrimp and fish fry. This extra cover can increase survival rates in breeding tanks.
Reduces Stress
Floating plants help diffuse harsh lighting and create a more natural environment. Many fish and shrimp become more confident when they have shaded areas available.
Why People Hate Duckweed
It Grows Fast Very fast. A small handful can become hundreds of plants within a few weeks under strong lighting and nutrient-rich water.
It Gets Everywhere. Duckweed has a habit of sticking to nets, hands, airline tubing and maintenance equipment. Removing it completely can be surprisingly difficult once established.
Blocks Light. If left unchecked, a dense duckweed mat can prevent enough light from reaching plants growing below.
Can Be Difficult To Eradicate. Many hobbyists discover that even after removing what appears to be every piece, a few remaining plants quickly repopulate the entire aquarium.
Is Duckweed Right For Your Aquarium?
Duckweed may be perfect if:
You keep shrimp
You breed fish
You want natural nitrate reduction
You enjoy low-maintenance floating plants
You prefer a natural aquarium appearance
Duckweed may not be ideal if:
You enjoy open water surfaces
You run high-light planted tanks
You dislike frequent plant thinning
You want precise control over floating plant coverage
Our Verdict At Fresh Start Gardens
We’re big fans of duckweed for shrimp tanks and breeding setups. Its ability to provide grazing surfaces, improve water quality and create natural shelter makes it one of the most useful floating plants available. Like any plant, it simply needs occasional maintenance to keep it under control. Love it or hate it, there’s no denying that duckweed remains one of the hardest-working plants in the aquarium hobby. Have you joined Team Duckweed or Team Remove-It-All?