It's a chemistry thing. Around 50-110ppm is the range you'll want for magnesium+calcium in the water. Less calcium than magnesium is needed for scale building. So ion exchange filters try to remove or replace most of the calcium to leave the water around 75ppm with more magnesium than calcium. If you remove too much of those ions(

@@TimtheWinzard There's really nothing about that that is correct. You need less Magnesium for scaling to occur than Calcium. It's the value of hardness "as CaCO3" along with the alkalinity "as CaCO3" from bicarbonates that determine scaling potential at a specific temperature. In terms of volume of scale Magnesuim scale may be less than Calcium scale, but not by weight. You also will not see corrosion because of a lack of hardness but because of acidity from dissolved carbon dioxide, so it is important for water to have sufficient alkalinity to stop it from being aggressive. You can have alkalinity without hardness by adding sodium or potassium bicarbonate to distilled water. If you have very high alkalinity and low hardness you will see scale forming just as you will with very high hardness and lower alkalinity, so you can't look at 'minerals' as ppm and determine scaling or corrosion potential. You can also see corrosion due to other things in the water such as chloride and sulfate.

i could be way way way wrong here, but isn't this all kind of the same concept/principle as cation exchange capabilities in soil? (note im a math guy, not chem, so im not retarded, just ignorant lol)

yes.

@@1st-lineequipment Thanks!

Yes sure. But it needs its time to soften. I would do as Joe recommends: put the Oscar in a pitcher with water and this in a fridge. Fill up your tank with this water after it has softened (depending on your water, the Oscar might need up to 24 hours to soften your water. And you need to be aware, that a two hours softened water is totally different than a 24 hour softened water so not easy to have consistent water quality

Yes but you need to remineralise to an alkalinity around 40-50mg/l to stop it being too aggressive. You can use sodium and potassium bicarbonate to do that and you wouldn't have to worry about scale. Add hardness (Magnesium or Calcium) by adding things like epsom salts and calcium chloride and you increase the risk of corrosion (from chloride and sulfate) and also risk scaling in a service boiler (mineral content can obviously be controlled much more easily in a brew boiler). "Softened water" is a meaningless term not specific enough to be useful advice. You can have very hard water with high alkalinity e.g. 250mg/l and 'soften it' by exchanging most calcium and magnesium ions for sodium, but you'll still get scaling because of the extremely high alkalinity and some remaining hardness, and your espresso will taste like crap too.

No, I don’t think so. But they’re that cheap, that it’s not really needed.

what’s the ratio recipe?