Have been doing daily fin-level water changes for these tiny guys (2g bowl) since day one and feeding extremely lightly. Right from the get-go, one of the two ( a pale, not so healthy looking silver/grey colored comet) didn't look or act healthy. He passed away some time last night and went the way of the porcelain swirl water park. Swim on little guy... Swim on.
Like said, the way these poor buggers are 'manufactured', kept and sold, it's no wonder.
The remaining orange comet is a real happy, active and colorful bugger.