Hello all,

I did my best to research and look up how to filter and treat water for my machine.

I reach the point where I need to use bottled water for a while for my machine until I can use proper plumbed in solution.

Is this water good and safe to use? I may end of using this a long time (1-2 years).

The PH level is around 6.7. Would greatly appreciate an expert opinion on this.




Thanks!

That looks like RO water that has had magnesium sulfate added. It should not cause scale problems, but the somewhat high sulfate (at 86 mg/L) combined with the very low alkalinity make it less than ideal for corrosivity reasons. Most advice recommends that you have an alkalinity above ~ 40 mg/L CaCO3 equivalent, and the alkalinity of this water (based on carbonate and bicarbonate numbers) is only around 1-3 mg/L CaCO3 equivalent.

Thank you for the detailed info.

Would the below water be better or the first one is safer?

Ahmad H. wrote:Thank you for the detailed info.

Would the below water be better or the first one is safer?
image

No, the chloride is bad there.

If you're buying water, just buy distilled water and mix in some minerals, something like this: https://www.baristahustle.com/blog/diy- ... o-bottles/

Unfortunately I'm not able to get distilled water in big quantities.

I may end up using the first water I posted above, unless someone advise to not use it.

Ahmad H. wrote:Unfortunately I'm not able to get distilled water in big quantities.

I may end up using the first water I posted above, unless someone advise to not use it.

Since you know the numbers on that water, you could just add magnesium sulfate (epsom salt) and bicarbonate as noted in the recipe(s) I linked, adjusting the magnesium down for the 20ppm that's already there.

Forgive my ignorance, what is the purpose of adding the salt and baking soda? Is that to increase the alkalinity? Or just for better taste water for coffee extraction?

Joe is correct -- too much corrosive chloride ion in that second one.

You can use that first water with no worries if you bump the alkalinity a little:

To an empty 1 liter bottle add 2 2.8 grams of baking soda (sodium bicarbonate) and fill to 1 liter using that first bottled water and shake well. This will give you a nice concentrate with about 1650 mg/L as CaCO3 of alkalinity.

Then to make your final water add 30 g (or 30 ml) of that concentrate to each liter of that first bottled water. You will end up with a water with 83 mg/L total hardness as CaCO3 and 51 mg/L alkalinity as CaCO3. The hardness here would be almost all magnesium and at that level it should not scale.

You could use 2.4 3.3 grams of potassium bicarbonate instead of 2.0 2.8 grams of sodium bicarbonate if that's available. (Some think potassium might have a taste advantage.)

The purpose of adding this is to increase the alkalinity, which helps raise the pH and buffer acids, and is advised for both taste and especially for machine health.


Edited 2/25:
Oops, I originally used the molar mass of HCO3 rather than NaHCO3 causing this calculation to be off. Corrected that.

Ahmad H. wrote:Forgive my ignorance, what is the purpose of adding the salt and baking soda? Is that to increase the alkalinity? Or just for better taste water for coffee extraction?

As homeburrero says, the bicarbonate is for alkalinity which is for both machine health and taste (the taste here is a buffer for acidity). Adding more magnesium sulfate (epsom salt) will increase the general hardness which will increase extractions in general and in my opinion lead to better taste. Plenty of people use very low hardness waters though and are happy so you could try this part both ways.

Thank you for the help.

I'll start doing that today by adding baking soda to the water with the formula you provided.

I buy the first water in 17.5 liter jugs. Based on your formula, I should use around .98g of baking soda for 17.5 liter water jug? Just want to make sure my math is right.

Appreciate your help!