Well they don't really look like grains, and in fact they are not a grain at all, rather an organism.

The history of water kefir is not well known. It's hard to say just how far back mankind has been
using these grains because of a lack of recorded history, but it is at least many centuries if not
longer. Though similar to milk kefir grains, one cannot be made from the other, they are distinct
and separate cultures with separate (and largely undocumented) histories.

According to a combination of research and speculation, its origins most likely point towards
Mexico, where in 1899 M. L. Lutz documented its existence in the naturally sugar-saturated water
of the Ountia cactus (the prickly pear).

There is also a similar story of water kefir originating in Tibet much further back, when monks
gave Mother Teresa of Calcutta the grains as a gift. Another story suggests that they were
introduced to Europe (the Ionian Islands) and the west by the British Soldiers after the Crimean
War in the 1800's. This story however most likely refers to the Ginger Beer Plant which is
extremely similar to water kefir, but a separate culture. Some suggest that one might have even
evolved from the other long ago. Water kefir has also been reportedly used in close vicinity to
where milk kefir grains originate, in the Caucasus Mountains.

Basically they are an excellent source of broad spectrum probiotics.  When you drink your own water kefir you are guaranteed they are alive, they are virtually free, so arguably the best probiotic nature has to offer us.  

There are so many different ways to keep your kefir water, so do some research. In doing my Internet trolls I found out there were lots of things different people said you 'must' do in order to keep water kefir grains, but they were nearly all different.  In effect, that research has taught me that these grains have been used for thousands of years, and they are pretty tough and there are not many rules :-)  I've killed mine off twice and brought them back to life!

We store it in glass with a sealed lid. To the kefir grains we add a tablespoon of rapadura (you can use any natural sweetener except honey.  Honey being an antibacterial will kill it!).  Add to that filtered or bottled water near to the top of your container.  When you start with a small amount of grains, start in a smaller jar. Everyday (or when you remember like me), strain the kefir grains, the liquid is what you drink, and the grains are what you start again with.  It really is that simple.  When you first start try to do it every day so they can get well fed and revived.  We find the rapadura gives it a nice flavour, and the brown colour.  If you use raw sugar you would expect a white liquid.  You can add ginger or dates for flavour too.

You will notice a little pop when you open the lid, like opening a nearly flat soft drink.  You'll also see bubbles and they will rise to to the top.  The grains themselves rise to the top on occasion too.  If you see none of this for a few days you might have it in a too cold spot.  If they are dead or dying you will get a nearly dirt like taste, not sweet and sharp at all.  As I said above, I've killed mine twice, once when I first got them.  I left them in the packaging for a week without food or water.  But they revived after a week.  Then again I left it in the cupboard for about 6 weeks and revived it recently.  If you are going away, or if it's producing too much for your family, they say put it in a colder place, even the fridge.  This will put them into hibernation.

We have taken to straining it off and putting the water in the fridge, that way it's refreshing and I think tastes better too.  Whenever I think of it I take a little sip through the day.  I recommend you start slowly.  Just a sip a day then build it up.  You can also use Kefir Water to do a sour dough starter.  There are lots of recipe's on line, so have fun exploring!

I have started selling mine for $10 plus postage.  Send me a message with your email address, and I'd be happy to get some organised for you.