My fish were scared of it too for the first week or so, I use the magnetic clip so it can be pulled down nearer to the mid lower part of the tank ,now they are use to it my tang will choose that over frozen that has just gone in .The foxface is relatively new (a few months) and hasn’t touched it either. He’s very skittish and scared of it. My wrasse hides also when I put nori on the glass so it’s kind of a pain.
I’ll keep trying, I know it’s important. I put some in their dinner food tonight.
If I recall correctly, the foxface diet should be 80% algae .