I have a 12gl fluval edge tank, it has a small 5"x7" opening. I am growing flame moss as my background. I need to trim it periodically to keep it growing nicely. However it is a pain in the #@$! to remove the flame moss cuttings as they do not rise to the top like hairgrass or stem plants would. I have been looking for some form of powered vacuum hose like the one shown in this planted tank maintenance video (please skip to time 3:10):
No, thats not it. I've tried that gravel vacuum you linked, you need to shake it or pump to start suctioning and it has nowhere near the power of the one in the video and it is also wide, has no attachment so I risk catching my shrimps.