Hard coating / pattern on glass

[Azreefr]

Can anyone identify the hard coating that occasionally grows on my glass? It always grows with the same pattern.

 

[Ubergroover]

following....

 

[Eddie Rogers]

Kind of looks like algae that’s snails where eating

 

[cloak]

What kind of invertebrates do you have in the tank? It almost looks like some form of algae growth and then a snail or perhaps something else has been eating it. (hence the pattern)

 

[Azreefr]

I have one large margarita snail and several trocus snails. It may be the snails but the patten seems too uniform. This stuff has to be removed with a scrapper but it’s softer than coralline algae.

 

[LBReefer]

Yup, that’s evidence of an algae grazer. My back wall has a ton of similar markings from the blenny, snails and urchin.

 

[Bayareareefer18]

+1 to snail trails

 

[Azreefr]

I’m glad to know it’s not something else.

 

[Azreefr]

Happy to hear its not something that is going to take over my tank.