Board Thread:General Discussion/@comment-24108807-20140308010851/@comment-263019-20140308031327

Triple Challenge is the most efficient way of farming both health and mana potions. Guardians can access it directly via the teleporter in the Guardian Tower, while Adventurers have to mix a teleportation potion in Warlic's shop (Magma Leaf + Mermazon Kelp + Slattwob Dust, may send you to Talk Like a Pirate Day instead)

If you're too low level for Triple Challenge, there are a few quests that give potions. Frogzard Hunter 3 gets you up to 10 health potions, Frogzard Hunter 1 gives you one health potion, The Dark Forest gives you two health potions (though one is consumed unless you flee from the enforcer), and Yonder at the Crossroads awards one potion of each kind per battle (Adventurers can access the Crossroads by getting a Travel Pass from Valencia)