I will not drink "the stuff" they present as recycled water. I buy mine on shore and bottled.
You can take gallons of it back on ship if you want, as the only thing the ship "policemen" are interested in is alcohol coming on board, as that is seen as "robbing the ship" .
Ship "recycled" water is one thing, its free. But buy a bottle of pre packed water and depending on the ship, you can be talking $6 for less than a litre....
Buy it ashore and stick it in the cabin fridge.
ps I also do the same for canned Cokes, Sprites, etc. Not being cheap or mean, just not prepared to be a "patsy" to ridicules ship pricing for some products.