Though I have experimented with the recipe a bit (with a few awful results), I am now basically sticking to the original recipe given to me by the crystal provider and one that produces a tasty lemonade like probiotic drink with a bit of carbonated fizz...and that recipe is:

Kefir Water Crystals (I only have 2 tbsp or less)
1-2 tbsp organic sultanas
4-5 cups of water
4-5 tbsp of white sugar
1-2 slices of lemon with rind on
1 piece of egg shell

Hints:

Sugar rule of thumb is 1 tablespoon of sugar per cup of water. I used raw (brown in colour) sugar at first and later decided to try white sugar. When I went back to raw, a bitter taste that reminded me of licorice or molasses was very apparent and I didn't like it. So I am sticking with white sugar because taste is important if it is not too compromising, and in this case it is not because the crystals break down the sugar (sucrose) into fructose and dextrose and consumes much of the sugar and sweetness anyway. For the scant amount of nutrition I am missing in the raw sugar vs. the bitterness I can taste in it, I'm not bothered.

The lemon zest (bright yellow outer peel) contains the lemon oil. I have taken the zest off a few times because the lemon was not organic (so I could not be sure if it had anti-fungal or pesticides), and the resulting drink was not lemony. I have since left the zest on with even non-organic lemons and my crystals and I are fine.

I have read in most places that the crystals need to be rinsed after each batch, and though I did this faithfully for weeks, I've decided not to do this any more saving me an extra step. I have read about storing large amounts of crystals in simple sugar water in the fridge and then needing to rinse them once a week or so. I can understand that. But with a tiny amount of crystals, they get quite a good rinsing just by adding them to the 5 cups of water. Taking this a step further, a friend of mine whom I shared some of my crystals with came up with the great idea to treat the kefir water like kombucha, vinegar, etc., and keep a cup of the kefir water back to remain in the jug for the next brew. I imagine like most ferments, the new water just needs inoculation. The crystals provide this, but even greater/quicker inoculation occurs when 1/5 of the water is already turned. That's the thought anyway. And it makes sense to me and seems to be working.

The recommended water is high-mineral content water, such as well or spring water. I have even read from many sources that to use filtered water your crystals will not thrive and could die. Apparently to use chlorinated water is worse. Now, I have not used chlorinated water because I have a water filter at my sink and I don't drink chlorinated water either. So I can't say what will happen using chlorinated tap water. Initially I purchased and used spring water. I then tried using filtered water. I personally have not seen any difference. I also haven't done stringent long-term tests. I think one of the points about water is the PH level of the water for optimal fermentation. I have to say that this is beyond my scope and I don't test my water. Some instructions say to add a tiny pinch of bicarb soda for alkaline balance. I can't say one way or the other. I have tried putting in a pinch of bicarb. Again, I haven't made a serious attempt to compare this or test the PH. At the moment, filtered water is working for me.

The eggshell is also supposed to help with this aspect of the water since the kefir seems to break down the eggshell adding alkalinity to the water, I assume. And as a bonus, giving some calcium and magnesium to the drinker. Is it integral though? I don't know. I boiled a bunch of eggshells so I put in a piece and leave it in the jug for each batch until it is dissolved. It doesn't hurt and maybe it really helps. And I don't mind knowing I'm getting the extra minerals.

I like to use organic sultanas since I can easily get them at the grocery store because it is nice to know they have not been sprayed with stuff, don't have sulfites, and also because they don't have vegetable oil on them which does put a small oily film in the brewing vessel otherwise. I like the taste sultanas give. I read a bit of a scientific paper that I found in my searches that said dried figs proved to be optimal for fermentation. I tried figs a few times and I think it may have fermented faster or differently. But in the end I still like the taste of sultanas and taste does factor into this because I drink this every day and I want to enjoy it. The taste of figs might well appeal to others though, so definitely try it.

Instructions (how I do it anyway):

If you have a batch already made, use a tea strainer to scoop out the sultanas (that will float) and the lemon slice(s). I reuse the lemon many times as it continues to generate flavour. (During lemon season refresh each time if you like)! After about 5 days I squeeze the lemon into the finished product and throw the rind away. I reuse the sultanas 2-3 times. After that, their sugary life has been sucked out of them so I discard them (taste and see)!

Next, pour the liquid through a tea strainer (placed inside a funnel) into a bottle with hinged lid (see below). The strainer is to catch any errant kefir crystals or any lemon seeds. I leave about a cup of the kefir in the jug and usually the crystals stay in there with that final cup.

Cap your newly filled bottle and leave it out for a few hours to ferment it further or to get more carbonation. Further fermentation creates a bit of alcohol and if you leave it too long, you might get something very alcoholic tasting so be careful.

Add 4 tbsp sugar to 4 cups of water. Stir to dissolve, or don't. Add this back into the jug which still contains one cup of kefir water and your kefir crystals. Add the used/new sultanas, lemon and eggshell. The main point is to be gentle with the kefir crystals so as not to break them apart. I say this because as they get larger, it is not as easy to lose them and also at some point they apparently break apart on their own and liberate new baby crystals.

Put lid on jug and leave the jug out on the counter or in a cupboard or whatever suits for 18-48 hours. You'll have to taste test the water to learn how fermented you like it and how long that takes. Use a large capacity jug leaving plenty of extra room in the vessel because some pressure will build during the fermentation process and a full jug could explode (makes sense).


An experiment that wasn't so great...

I juiced a watermelon and used it for most of the water. I strained it and after several days in the fridge in a capped bottle, it was thick and really yucky. It took a couple of batches for the crystals to recover and produce a nice batch of the regular recipe.

I really love kefir water. I look forward to seeing and tasting my new batch each day. And each batch is a bit different. It is like seeing a new bloom on a rose bush. I think of it as alchemy, gardening and art combine. Something like that.

Please post if you have more to add, or your own recipe, or if you found different results, etc.