Of course they don't have it at petsmart/petco, but when I went into my two LFS they acted like I was asking for something that was really really rare! Makes no sense... one of the places had what he called 'half a portion' that was in peices in a few tanks, so he gave it to me when I bought some other plants, but I didn't expect it to be that hard to find!
...scary!
...scary!