She feeds them frozen bloodworms, not freeze dried, and the pellets are regular sized, but when presoaked, both boys have issues keeping down two pellets. Her bettas are no joke a little bigger than half the size of my boys.
The marimo balls had pieces of fungus on them too, and she didn't rinse them in hot water for more than a few seconds.
I'm not sure how well you can see it, but it was like a goopy and semi-clear glob with some fuzz on top. As far as I could tell, it was not mulm nor was it caused by decaying food. It was mainly on the decoration itself and had spread a bit to surrounding surfaces. GkFins bought that decoration one week ago and had rinsed it well before adding.