White buildup on interior tank glass?

[CombJelly Cuddler]

Anyone know what this is?

 

[TeeJay87]

Looks like coralline algae to me, which if true, is a good sign of a maturing tank. If a regular glass magnet cleaner isn’t enough to remove it (mine are plastic and don’t remove coralline) you can use a credit card or razor blade scraper.

 

[CombJelly Cuddler]

Looks like coralline algae to me, which if true, is a good sign of a maturing tank. If a regular glass magnet cleaner isn’t enough to remove it (mine are plastic and don’t remove coralline) you can use a credit card or razor blade scraper.

Oh that's good glad it seems to be nothing bad! Thank you.