You can order Indian almond leaves (IAL) online. But I also find them in the hermit crab section of my local big name pet shop. They come in sealed packages and are really nice. Also, many people on here seem to use organic rooibos tea bags in a pinch; just make sure pure rooibos is the only ingredient. If you can't find any of these, you could get some Attison BettaSpa or Amazon black water extract.
The more I think I know, the more I think I don't know much at all!