The stuff that's processed (ground up and the pressed back into sheets) is gonna fall apart but shouldn't do so very quickly. Same with the nori (I use it too). A trick to keeping it from doing so is not to leave long pieces sticking out of the clip. I tear a piece in two and then roll it up loosely, fold it in half and stick it in the clip. This gives you a good bunch but keeps it fairly short (close to the clip). It seems like the longer it sticks out the quicker it falls apart. There is an algae sold as Julian Sprung's Sea Vegies that is actually dried whole pieces of different types of seaweed. I really like the product but it is on the expensive side. I usually switch back and forth between it the nori.

So many species, so little money!