The hydro tank is NOT my farming build -- that is still my secret for now, but maybe I'll post the details of that at another time. And yes, the hydro tank is not used for pvp either -- it's primarily a powerful alternative to nuking in most areas of the game, and with it you can keep henchmen or even mediocre pick-up group teams alive indefinitely, a common problem for solo elementalists in pve. It can be used for farming, but it should be adapted significantly or, ideally, combined with another elementalist running a pure echo nuker build (like my farming partner Jeffy Jean!).