I broke my arm, got married, and had a baby girl all in the last year. My poor 24g nano has been neglected! It got angry with me, or was that my wife, for letting the tank get so well...whats the word...we will say grown.

As you can see I have no problem growing coraline algae! I tried getting it off with a mag float, fat chance. A scrubbing sponge, it laughed! A butter knife, capable but time consuming. My solution, a razor blade!

This little beauty was cheap at walmart and wow did it power through the coraline. I have not noticed any scratches as of yet, but then its been nice just being able to see my fish
