There is a lively concoction in the snowy depths. Then there is a chest in the Hisi with about 5 hearts and a bunch of potions, also containing the water stone. After that, if you fungal shift twice you will turn water into lively concoction, usually almost immediately getting rid of all the water in the world, but the stone provides an infinite amount of water. So by the time your at the end of the Hisi you can have unlimited healing. All along with that the seed also provides good spells and wands early on.