I just got the unknown fish in my tank identified as Rosy Barbs.
When I added half a cup of Duckweed to their tank saturday, I finally saw the culprits who always made it vanish magically.
Its these Rosy Barbs, Two of them ate a half cup of duckweed in less than 2 days. 8O
Just a heads up that these guys just destroy Duckweed, and their pretty to