Introducing duckweed (otherwise known as water lentil) to your aquaponics system is a great way to reduce the acidity and ammonia in your tank while improving your tank's sustainability. Duckweed can act as a nutrient-rich food source for fish, reducing the fishes' need for an outside food source and bringing your system closer to becoming a self-contained life cycle.
Step 1 - Obtain Duckweed Culture
Duckweed can be purchased from any pet store as it is a typical food for fish and livestock. You can also collect duckweed from any standing pond, though be careful; it may be a home for micro-organisms!
Step 2 - Mix Duckweed in Water Bucket
Fill bucket with fresh water, then put your duckweed culture inside. Allow to grow for 3 days to a week.
Step 3 - Introduce Duckweed Mixture to Aquarium
Pour duckweed into aquarium and allow to settle on top. Take care to spread it evenly across the surface.
Step 4 - Turn on the Grow Lights
If grow lights are available, place them above the tank and leave in place another week. This will give the duckweed the nutrients it needs to become a sturdy part of the aquaponic system.