Pure Shockfrozen Water

Created by first getting the buff in Tatooine and then a different buff from Hoth.
Once you have both buffs, the item will be placed in your inventory.

Great guide for the whole crystal here: http://dulfyforce.wordpress.com/2012/01/07/guide-advanced-magenta-crystal/

<edit> coords were wrong and added link.

Thought I'd add my experience of this in order to help others avoid the same pitfalls I fell into. As the link Unblessedsniper posted (good guide and all), and as AmunRA also said: The location of these water towers does indeed seem to be randomly placed. Mine wasn't even in the same zone.
Quoted from the guide:
Keep in mind that not all of the water thingies have the clickable so if the one you are on don’t have it then find another one in the area.

Now please vote up a comment stating this so it'll be more easily spotted :)

Apparently drinking this gives you around an 8.5k heal, and a "Refreshed and Sustained" buff.

Right-clicking off the buff will allow you to drink it again for another 8.5k heal. The water is on ~10 sec cooldown, and is infinite use.

I'm sure this is not intended, but that's the way it is.

Edit: it appears it only works out of combat, preventing it from being overpowered in fights, but still being quite useful in reducing downtime to near-zero.