It’s certainly welcome! This is a “learning tank”. I want to get a handle on growing the plants in general before investing in more expensive equipment and hardscape materials. Plenty of research to do! 🤓Looks like it to me. I'd think of it as a welcome hitchhiker- I, personally think it's pretty. If you don't like it you can scrub it off, just make sure you do it outside your tank, pieces that break off will grow- sometimes in the worst of places.