Watermeal
Identification
- Small oval or spherical-shaped floating plant
- Typically measures between 1-2 mm
- Feels grainy, like sand
- Green in color
Why Do I Have It?
- High inorganic nutrients
- Low surface water movement, and low flow
Associated Lagoon (Pond) Conditions
Watermeal can form a thin green scum layer and can be confused with the algae or cyanobacteria that form a “green paint” scum. Scums of watermeal can cause high effluent TSS that, depending on the permit, have the potential to violate limits.
Treatment
Watermeal can be controlled by applications of Duckweed Complete followed about two weeks later by spraying PondZilla Pro to degrade the dead watermeal. However, chemical treatment is not always recommended as a small skimmer can block watermeal from exiting the lagoon. This floating plant is a symptom of high levels of sludge buildup and internal nutrient recycling. Sludge can be physically removed by dredging or a non-disruptive option: SludgeRx. This can aid in sludge reduction and prevent resuspension of nutrients such as nitrogen and phosphorus.
If you’re concerned about excessive growths in your lagoon or pond, we recommend taking a few photos and sending them to your rep or info@teamaquafix.com. Our lab will look over the photos and advise on further steps.
Under the Microscope and in Your Plant
Watermeal is a small (1-2 mm), oval or spherical-shaped floating plant that thrives in nutrient rich environments. This plant is often found embedded within duckweed colonies. Watermeal can form a thin green scum layer and can be confused with algae or cyanobacteria that form a “green paint” scum.
References
index/watermeal/
Waterworth, K. (2021). Controlling watermeal weeds: Tips for managing watermeal in ponds. Gardening know how.
https://www.gardeningknowhow.com/ornamental/water-plants/watermeal/managing-watermeal-in-
ponds.htm