CathyWeeks wrote:I wonder how safe aquarium chemicals are? Fish are notoriously easy to kill, so my guess (not that I want to be a guinea pig or am recommending this) is that they probably aren't dangerous to humans.
I would only use food grade minerals and chemicals intended for human consumption.
RyanJE wrote:Or you could make the 70/30 water. Its just Mag Sulfate and Baking Soda in distilled water.
I think that's a common formula for purified drinking water - like commercially bottled water, Dasani and the like.
Global Customized Waters supplies RO + remineralization systems to coffee shops all over the world. They take the RO water and use a two stage mixture of solutions of calcium chloride in the first step, and a mixture of sodium bicarbonate and potassium bicarbonate in the second addition. The two react in dilute solutions in pure water to form calcium, sodium, bicarbonates, chloride and potassium ions. You can do this at home and make the concentrates yourself with pickle-crisp (calcium chloride) for the first mixture, and the bicarbonates (baking soda - readily available, you can order potassium carbonate food grade on Amazon). You just make the concentrates, then add them in two steps to a large volume of distilled or RO water. The only downside is that you wind up with some chloride ions.
If you believe the likes of La Marzocco and others, what you want is calcium carbonate hardness, with a minimal sulfate and little/no chlorides. http://lamarzoccousa.com/docs/tb/LMUSA-Water-Spec.pdf
I'm in the same boat. My tap water is too hard to use and when I tested it, it has way more chloride than recommended. Even blending with RO water from my RO system, I don't arrive with a proper balance of mineralization, at least the way La Marzocco sees it.
I looked into putting an inline mineralization cartridge after the RO system. They are somewhat unpredictable in the amount of calcium carbonate they can add and at most, only add a few points. Not enough to really get where it needs to be.
Calcium carbonate is funny stuff. It is only slightly soluble in water. It dissolves more readily in cold water than hot, and it forms bicarbonate from the dissolved CO2 in distilled or RO water. Heating it drives off the bicarbonate converting it to carbonates - which is exactly how scale forms.
One simple trick - is if your tap water is simply hard, but doesn't have a bad mineral composition, just boil it, let it rest and pour it off the scale or precipitate that it leaves behind. That boiled water will not scale your boiler as all the temporary hardness has been precipitated. If it has a good balance of minerals, without too much salt or sulfate, you have coffee water.