LOL it's not duckweed! It's the one snail I couldn't find when you were over last time!
I forgot about him and tonight I changed my substrate out.... And when i was walking by the pile of substrate in the bucket I glanced down and noticed him.... Lucky he was on top! He could have been barried alive under 10 pounds of substrate!
If you want him he's yours....
do your crays eat water lettuce too?