I had some small guppies/green fire tetra in my sorority tank as extra color and entertainment for the girls and was feeding them Omega One's First Flake. Problem is while it seems ok for guppies, mollies, tetra and even a Chinese algae eater... it stops up Betta guts like glue.
When feeding my flock of guppies in another tank the tank slowly developed a white "winter wonderland" of residue from the First Flake landing on the bottom. The flakes would lose their color and become a gummy paste.
It seems to be a material that is ONLY in Omega One's flakes, either First Flake or Tropical Flakes. Not sure if its gluten or a calcium substrate but an accidental over-feed that was snarfed up by four girls killed every one of them. No treatments for intestinal ailments were successful.
I'm gonna stop using the entire Omega One brand and go back to Hikkari Fancy Guppy pellets.
Thought you should know.