"When you pull/push this across the glass, it dosen't glid smooth. You could say that it make short jumps as it follows the handle on the outside of the tank. This effect makes a noise that scares my fish. It's almost intertaning >:-).
Now,...How well it cleans.....
First off, there seems to be two type of allge (that I've seen) that grows on glass. The scumy stuff that you can wipe off with your finger, and those little green spots that are as tough as barnicals. This cleaner will take the scumy stuff off in two pass. The green spoted kind will take 10 to 20 passes to remove it. So for this type of allge, it not as effective as getting your arm in the tank with a scatch pad, but some days it beats getting your arm wet."
