Ciaran wrote:I would get your water tested first before deciding what to do about it.
Or check with your water utility - get numbers for hardness, alkalinity, and chloride at your tap to help you decide. My quick look (https://www.saginaw-mi.com/departments/ ... uality.php
) indicates that your chloride is probably reasonably low and your total hardness is perhaps up around 110 mg/L. I don't see an alkalinity number (it's always good to have that.)
As far as your interim solution you have some simple options.
1. Use one of those in-tank pouch softeners. The Oscar and Rocket pouches have conventional cation exchange resins, much like you will probably have in your whole house softener. They should do the job of reducing hardness (preventing scale formation) and keeping alkalinity. They need contact time to work, so would be best to try to always refill your reservoir at night after you are through pulling coffee for the day.
2. Mix charcoal filtered tap water with your ZeroWater. If your tapwater is indeed only 110 mg/L hardness, a 50:50 mix would be good. Your fridge may have a charcoal filter. A Brita would probably be OK for this, even though it has some resins that reduce hardness and alkalinity.
3. Use your ZeroWater (deionized water) spiked with a little bicarbonate. Use only about 0.3 - 0.4 gram of sodium bicarbonate (baking soda) or potassium bicarbonate per gallon of ZeroWater. This would give you minerals for the sensor, and alkalinity (buffer) for corrosion protection, and have no scale potential and no nasty chlorides, sulfates, chlorine, etc. Many folks on this site have used this approach (aka "rpavlis recipe" , from the late professor R. Pavlis) and report good results. This one works irrespective of what's in your tapwater.