Hi guys.

So we finally bought our first home and Friday I finally got all the parts to fulfill my espresso dreams of plumbing in my machine.

I have a BWT Bestmax Premium filter with the adjustable bypass BWT head. I got it from whole latte love. My city water is 130ppm general hardness as tested with API titration kit. I installed a test port coming out if the filter before the linea mini to be able to check on the water and no matter what I set the head to the water is still 130ppm hardness, no idea what's going on or if something about what this filter does is messing with the test.

https://www.wholelattelove.com/bwt-best ... er-package

Help! Thanks -Anthony

It looks as though they are "substituting" magnesium for calcium and thus I would not expect the GH to change. BUT, you really should test your water to see that it meets/exceeds all of the LM water qualities.

http://www.bwt-wam.com/en/Technology/MG ... fault.aspx

Interesting. I would love to know more about this as well. According to my quick Google, hydroxide and carbonate form of magnesium have rather low solubility, which in my understanding will precipitate and form limescale. I would've expected the filter to soften the water, then reintroduce magnesium in a controlled/predicted concentration, rather than just substituting all the calcium into magnesium. The latter function alone is not sufficient for the BWT to qualify as a water softener.

I am certainly not a chemist nor a chemical engineer. However, this is an updated chart using LM's latest numbers. I only checked about 4 of their machines but I simply ASSUME that these numbers apply to all of their products.

Nice chart, Eric! You may not be a water chemist but you sure have a knack for putting together useful water information into these nice comparison charts.

FWIW, Nuovo Simonelli's Victoria Arduino Black Eagle does specify a max total hardness of 3 gpg (51 mg/l as CaCO3), which is a little lower than everyone else. See for example: http://www.nuovadistribution.com/images ... 0Sheet.pdf
It may be more than a coincidence that the WBC standard water spec hardness was dropped a little, to 51 mg/l in 2016, which is when the Black Eagle became the WBC official espresso machine.

Also, although it's correct that the BWT patented "Mg2+ technology" replaces Ca++ with Mg++ ions, I don't think that's all that it does. My understanding is that while some Ca++ is replaced with Mg++, their resin also replaces Ca++ and Mg++ with H+ ions (same as other Weak Acid Cation resins.) So you would expect a reduction in hardness as well as an equal reduction in alkalinity. See the BWT patent for more info related to that resin: http://www.freepatentsonline.com/20130306541.pdf

sluflyer06 wrote:My city water is 130ppm general hardness as tested with API titration kit. I installed a test port coming out if the filter before the linea mini to be able to check on the water and no matter what I set the head to the water is still 130ppm hardness, no idea what's going on or if something about what this filter does is messing with the test.

That is very surprising, but I can't say that I've seen tests and hard numbers. I thought that this filter had a WAC resin that was partially loaded with Mg++ ions, which were exchanged with Ca++ ions but that also softened the water via a typical WAC resin exchange with hydrogen (H+) ions. The exchange of Ca++ for Mg++ would lower your calcium hardness, but would not change the total hardness as measured by that API GH titration test. The exchange with H+ ions would be expected to reduce both your total hardness and your alkalinity by an equal amount.

Do you also test the alkalinity of your incoming water? Perhaps if that's very low it would explain the lack of softening. In any case I think it's worthwhile to ask WLL to contact the BWT folks for an explanation, ideally some example data on the effectiveness of this filter in reducing calcium hardness, and the effect on total hardness and alkalinity.

This may be of interest and is relevant to the OP. Some reported that the BWT filter softening capacity will improve after a few weeks of use. I've heard grinders need breaking in, but now it appears water softener also benefits from a break in process. Can we use the starchy water from rice washing to help speed up the break in process?

https://coffeeforums.co.uk/showthread.p ... iler-(BWT)


Just kidding of course on the rice water idea..

homeburrero wrote:That is very surprising, but I can't say that I've seen tests and hard numbers. I thought that this filter had a WAC resin that was partially loaded with Mg++ ions, which were exchanged with Ca++ ions but that also softened the water via a typical WAC resin exchange with hydrogen (H+) ions. The exchange of Ca++ for Mg++ would lower your calcium hardness, but would not change the total hardness as measured by that API GH titration test. The exchange with H+ ions would be expected to reduce both your total hardness and your alkalinity by an equal amount.

Do you also test the alkalinity of your incoming water? Perhaps if that's very low it would explain the lack of softening. In any case I think it's worthwhile to ask WLL to contact the BWT folks for an explanation, ideally some example data on the effectiveness of this filter in reducing calcium hardness, and the effect on total hardness and alkalinity.

Thanks everyone for taking some interest. My water supply alkalinity is 50ppm(3d) on KH API test which is the same I got out of the filter.

Even if the filter is replacing all the calcium 1:1 with Mg, that still scales and would be a no go for protecting my machine as I understand it.

I can't dig up much any coffee specific data on the internet about BWT products except a old thread about someone in California with 300ppm GH and that his BWT setup couldn't remove about 1/2 of that and he ended up going to Chris' commericial softening setup but my water is not nearly that hard.

I was making my own water from distilled + magnesium sulfate, sodium bicarbonate, and potassium bicarbonate targeting a GH of about 40 and alkalinity around 50 and my tests showed I was on point with that, If I'm interpreting Jim Schulmans charts, to protect my steam boiler my GH really needs to be under 50 if Alkalinity is 50 or I will develop scale.

Sorry to double post but I just read through the Coffee Forums UK thread as well as another BWT thread linked inside of it, it seems almost like BWT designed this setup to make water that would be great for extraction while doing SOME softening, but I don't see any examples where the hardness is being reduced to non scaling levels, I do understand the dichotomy of water thats good for extraction vs water that will leave my setup scale free, and I'm not willing to get the extra few % of flavor out of my shots at the expense of getting scale buildup.

I feel pretty misled by this product if everything I'm seeing is like I think it is.

Before I switched over to the standard CCS 10" filter IX combo, I used the BWT filter. Besides finding issues with scaling, the method used by this filter tends to reduce pH to acid levels.......not too good a situation for typical dual boiler materials...