I used to have some in my frog tank, and they loved them. The pots seem to be completely safe as long as they have never had fertilizer or anything in it. I bought mine at a craft store. The only thing I would suggest is to put it in a container of treated water before putting it in the tank because it fizzes a little when you first put it in. That goes away after a while and probably would not hurt the fish, but it might bug them.
HTH!
ETA: Missed a word and it changed the whole meaning...
Amber
Last edited by stampingchick; 11/02/05 02:55 PM.