RoastedRob wrote:My question is at what TDS do you recommend we set it at and for how long to dissolve the scale? Do we just run it as usual?
If it were me, I'd dial it down til the alkalinity was around 40-50 mg/L. Your RO people probably have a kit to test that. You can test it yourself with an inexpensive kit sold online and in pet stores: API GH & KH Test Kit
. If the espresso tastes good at that level I'd just stick with it.
RoastedRob wrote:I assume running it at straight 0 will cause probe level failure.
Even at zero bypass I think your level probe will work fine. They don't require much; a conductivity meter reading of 5-10ppm should be plenty, and even if you have a very efficient RO, given the high TDS of your incoming water you should have that much conductivity at zero bypass. The downside of very low TDS would be that it would also be very low alkalinity and over the long run may cause corrosion. Over the short run, assuming you do have scale deposits built up inside your machine you don't need to worry about low alkalinity and corrosion.
RoastedRob wrote:... they are using a bypass blending method to hit the 150 TDS recommended by the SCA. Maybe in the long run for the life of the machine we should shoot for lower TDS?
That SCAA recommendation of 150 TDS should not be taken too seriously. For one thing, the SCAA did their measurement using a TDS meter calibrated differently than yours. If they had used an HM digital meter with a calibration factor of 0.5, their 'ideal' water would have read more like 115 - 120 ppm. I think the best approach is to adjust the bypass so that the alkalinity is at least 40-50 mg/L, then maybe
bump it a little higher to get the hardness up in the 50 - 80 mg/L range if you think that improves the taste of your espresso, AND if the hardness and alkalinity numbers are still OK with respect to scale deposits. (The (FAQ
) that I mentioned earlier can help with that, and is also referenced in the water guidance in some of the Kees manuals.)
RoastedRob wrote:I believe they are adding a carbon filter before the RO to help with the chlorine. We've had some water problems recently here which is why the chlorine has been added to the city water. It has caused a lot of problems but I am very relieved that my brand new machine can be helped back to normal and I can sleep at night now. haha
Good to hear that.
P.S. Are you running a coffee shop? I don't think I've ever seen a Kees Spirit in a New Mexico shop, would be fun to visit if you're agreeable to sharing your shop's name and location.