There's actually no current in there, they're on low-powered sponge filters, but good thought! I hadn't even thought of that. :)
The tubs (lol!) are just that...big white tubs that I got that are actually for dishes, but they make great holding and QT tanks for fish and for plants. ;) I put in some water and dumped the floaters in there until I could get the rest of the tanks set up (going from 6 with silk plants to 6 with live plants...takes some time and some planning, lol!) and thought that with adequate light and some nutrients they could stay there in a "holding pattern" until I could get around to putting them in.
They were happy for the first week and a half, then I thought they probably needed some flourish, in it goes, and within two days they were starting to die off. I dosed again a week or so later, and the final die off occurred another 48 hours later. Same with the tank I have some in...I was letting everything get settled and happy, plants seemed to be growing well with just fish for fertz, but I thought it might be nice to add a little bit of "food" in there for them so does with flourish, and two days later, dead dead dead. :P
It may not be the flourish, it could be some weird coincidence, but that's the *only* thing that's changed that I can think of. :P
As for the "fairy moss", lol! That's just what my LFS calls it. It looks like tiny, tiny little fern leaves, individual little leaflets. It's very pretty, and I really like it. I'm planning to get some more tomorrow (they carry it in their pond section which they're clearing out for the winter, so a huge softball sized portion only cost me a 1.50...I mean, you can't go wrong with that.) :), so I'll try it this time with NO flourish and see if that changes anything.
Thanks for the information though, and if that is azola, let me know, lol! I'm awful about knowing the names for things. :) I tend to buy "loose" bunch plants at the LFS's around here, and often they don't have tags or names...I just buy one or two, see if they live, and then go from there. :)