puke

There's this white filmy stuff floating around in my betta's tank. She's female, and the tank is 2.5-3 gallons. The stuff gets everywhere and it's really hard to clean up. She's otherwise very healthy. Energetic, always moving, regularly taking in oxygen, etc. I do 40% water changes every day...

I feed Lucy bloodworms and flake food. However, I am noticing that she will puke out the flake food and try to eat it again. This has started happening more frequently. I have searched this site for a possible explanation, but I am 100% certain Lucy is in perfect betta health otherwise. Is...