I've been thinking about adding azolla to my tank or something similar such as salvinia. I'm probably too far from you to get yours though. Jus out of curiosity however: do you find the azolla to be less invasive than duckweed? I like a small amount of floating plants in my tank but have been struggling to get rid of a duckweed infestation for AGES.
Duckweed is far more difficult to get rid of (I like to refer to it as "Aquatic Herpes"). Azolla filliculoides, And Salvinia minima are both good growers but easy to remove completely if needed. I keep both azolla and salvinia together as floaters in my tanks. They also are excellent Dwarf Rainbow egg traps for me.
thank you!!! That makes me much less nervous about adding some lovely floaters!
That is SUCH an accurate description of duckweed... I added some to one old tank about 3 years ago for the goldfish to eat. I sold that tank about 2 years ago... still somehow have some in my little tank. I think its almost eradicated though.