Can you help me identify what is on my glass?

[tjtax]

It seems hard and when I tried to scape it off it was pretty resistant to scraping (I was using my sponge “scraper”).

 

[Sharkbait19]

That’s coralline algae - hard to remove but it’s a good thing!
It’s a sign that the tank is maturing and become more stable.

 

[8-Bit Reefer]

Just use a good glass scraper and it''ll come off easily, the longer you leave it on there the harder it becomes to remove

 

[Reefkeepers Archive]

Coraline algae! A sign of a healthy tank!

 

[kevgib67]

I try to keep it off the glass on the front and sides. If you don’t like the placement and it is stubborn use can use a razor blade and the parts that come off will seed your tank.

 

[Idech]

Coralline algae but is that an aiptasia in the back ? If so remove it before it spreads.

 

[tjtax]

I believe it’s a spaghetti worm.

 

[EeyoreIsMySpiritAnimal]

I believe it’s a spaghetti worm.

*Hair worm