The Salvinia in my 40B is overgrown and instead of dumping it in the compost later this week, I can bring some for free for any members who would like some and are going to the picnic/BBQ. I should have 3-4 portions. There is probably some duckweed in with it, although it actually overwhelms duckweed pretty well in my tanks. And I definitely can't promise it is snail (or snail egg) free. If that doesn't scare you off, just reply here if you are interested.