Pest identification
What's eating my wolffia arrhiza?
Algae (green water / filamentous)
Signs: Algae mats smother the minute fronds and block light; nutrient competition causes Wolffia colonies to thin rapidly.
Control: Keep water nutrient-lean, use gentle aeration, and remove algae by partial water changes; UV sterilisers help in recirculating setups.
Fish and shrimp (aquarium grazers)
Signs: Fronds eaten wholesale; even small fish like guppies or goldfish browse Wolffia actively.
Control: Culture Wolffia in a separate snail- and fish-free vessel; float a fine mesh barrier if kept in a community tank.
Aquatic snails
Signs: Fronds rasped and fragmented; high snail populations in a closed system can eliminate a small Wolffia colony quickly.
Control: Keep Wolffia cultures snail-free; hand-remove any snails promptly and quarantine new plant material before adding.
Keep wolffia arrhiza pest-free
Healthy plants resist pests best. Get the basics right:
Wolffia arrhiza pests — FAQ
What is eating my wolffia arrhiza?
Wolffia arrhiza (rootless duckweed, the world's smallest flowering plant) is kept indoors in aquaria or culture dishes. Its chief threats are algae outcompeting it and fish or snails consuming the tiny fronds. Water quality decline — excess nutrients causing bacterial bloom or pH crash — can wipe out a colony faster than any conventional pest.
How do I get rid of algae (green water / filamentous) on wolffia arrhiza?
Algae mats smother the minute fronds and block light; nutrient competition causes Wolffia colonies to thin rapidly. Keep water nutrient-lean, use gentle aeration, and remove algae by partial water changes; UV sterilisers help in recirculating setups.
How do I get rid of fish and shrimp (aquarium grazers) on wolffia arrhiza?
Fronds eaten wholesale; even small fish like guppies or goldfish browse Wolffia actively. Culture Wolffia in a separate snail- and fish-free vessel; float a fine mesh barrier if kept in a community tank.
How do I get rid of aquatic snails on wolffia arrhiza?
Fronds rasped and fragmented; high snail populations in a closed system can eliminate a small Wolffia colony quickly. Keep Wolffia cultures snail-free; hand-remove any snails promptly and quarantine new plant material before adding.