So I just received duckweed today that I bought on EBay. I bought it in hopes that my goldfish would find it a nice snack, plus it may help decrease my nitrates in the long run. This is also the first time I've ever added a live plant to my tank. I dumped the leaves in a strainer, gave it a "good rinse," drained it, and then put it in the tank. Afterwards I saw 3 snail shells at the bottom, immediately scooped them out and put them in my 1 gallon bucket. Looks like 1 of the 3 is alive. So now I'm a bit scared for my fish; I have a bad feeling that I might have introduced some bad bugs/parasites into my system. Is there any preventative measures that I can do to make sure there isn't a breakout? Can duckweed withstand salt?