What are these all over the glass

[cylon032]

Can anyone help me id these, they’re all over the glass, are they good/bad?

 

[Ultra Aquatics]

Flatworms, usually they die off on their own in my experience.

 

[LuisPerez711]

Flatworms. I believe they die off naturally in low nutrient systems. If they don't, you could get fish that prey on them. I believe a lot of wrasse feed on them (six line, melanarus, coris, etc.). I heard mandarin fish also feed on them but it looks like mine leaves them be. It's probably because he's too busy feeding on the pods in my refugium lol good luck!

 

[cylon032]

Thank you!!!