i bought mine on ebay. and they worked great. they haven't caused any problems for my frog either.....they take a little bit about a month... i think. i'd have to look at the directions agian... lol but its worth the wait. once they start popping out they grow like daisies.
this is the one i used. Glow in The Dark Mushroom | eBay just look around you might be able to find other deals on ebay for same brand cheaper or on other places. hope that helps.