Duckweed | Lemna minor or Spirodela polyrhiza
Duckweed Species
Scientific Name: Lemna minor, Spirodela polyrhiza
Common Name: Duckweed, Devil's Spawn
Duckweed is an extremely fast-growing floating plant, and once introduced to your ecosystems, it is difficult to remove. It's great at reducing the growth of algae while also providing shade for inhabitants, increasing surface area, and reducing nitrates in the aquarium. Duckweed can also be used for shrimp food when blended into a paste and dried (add spirulina powder to enrich it). It is also an ideal food source for Goldfish!
You will receive one (1) portion of duckweed. One portion is equivalent to a ping pong ball size. One portion is a good start for a 10-gallon aquarium. We rotate between L. minor and S. Polyrhiza and cannot guarantee which species you will receive.
Caring for Duckweed in Blackwater Aquariums
Care Level: Easy
Lighting: Medium
CO2: Not Needed
Tint Tolerance: All (floating plants thrive in all tint conditions)
Origin: North America to Northern South America
All Plants may contain snails or snail eggs. We keep them in all of our tanks for the benefits they provide. Our blackwater aquarium plants are provided by H2OPlants in adherence to their Shipping and DOA Policies. Your curated selection will arrive in their packaging separate from your botanical & merch orders.
Duckweed | Lemna minor or Spirodela polyrhiza
contrast the tint with greenery
While the aesthetic appeal of tinted waters can be quite attractive to us, the recreation of nature—which includes both submerged and emersed plants—is the end goal. Flora helps to improve water conditions, feeding patterns, spawning displays, and territory building.
Aquatic Plant FAQs
DOA Policy
Please ensure that you add a heat pack or cold pack to your orders if temperatures in your area are above 90°F or below 40°F. Click for more info on our DOA Policy.
Are these plants duckweed and snail free?
All Plants may contain snails or snail eggs, small macroinvertebrates, and duckweed. We keep them in all of our tanks for the benefits they provide. We have experienced the presence of small snails, ostracods, daphnia, and beneficial detritus worms.
Are your plants only for tinted water conditions?
Nope! All of our plants will grow perfectly in untinted aquariums that have CO2 and aquasoils, or low-tech planted aquariums. Our selection, though, is optimized for emersed plant growth and low- to medium-tinted water environments.
What is your aquatic plant shipping schedule?
We’re a small company and ship Tuesdays & Thursdays only. Orders placed Wednesday–Sunday → Ship Tuesday. Orders placed Monday–Tuesday → Ship Thursday
Are your plants just for bettas?
Nope. Our aquatic plants are safe for almost all aquariums, terrariums, vivariums, and paludariums. Many of our plants can be grown emersed in filter compartments, vivariums, or incorporated into wabikua.
What are Tannins?
Tannins are natural compounds released by leaves, seed pods, and bark as they decompose in water. They soften water, gently lower pH, and create the characteristic tea-stained tint found in blackwater habitats. But their role goes far beyond color—tannins fuel beneficial bacteria, fungi, and biofilms, which form the foundation of a healthy ecosystem. They also offer mild antifungal benefits and help reduce stress in fish by replicating the natural conditions they’ve evolved in. At their core, tannins are plant-derived antioxidants that connect your aquarium to the same processes at work in wild flooded forests and streams.