Cleaning glass

[BabyShark]

Does anyone know what this is called and the best way to clean it?

 

[Idoc]

It might be coraline algae if it's hard and really sticking to the glass. If so, elbow grease and a razor blade or paint scraper works.

 

[lilgrounchuck]

Second the above. Every color of it in my tank starts out as hard, brown circles. Only choice is scrubbing and scraping, unless you get urchins. I’ve got acrylic and found a magic eraser to be the best tool. I also put two urchins in and they do a pretty good job of chompin it down.

 

[redwayjay]

mag-float and a razor blade.

 

[gotmesalty77]

Flipper makes a great cleaner. I love mine.