BWT vs. Oscar reservoir pouches in Napa CA?

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.

#1: Post by mycatsnameisbernie »

I'm interested in eliminating the need to descale my setup in Napa, California. I am currently using tap water in my machine's reservoir with a BWT Bestsave M in-tank pouch.

I have an API GH & KH test kit which I frequently use to test my water. The water out of the tap measures a GH of around 6 to 8 drops ≈ 108-140 ppm, and KH around 5-6 drops ≈ 90-108 ppm. After treating with the BWT pouch, I measure GH of around 3 to 4 drops ≈ 54-70 ppm and KH of 3 drops ≈ 54 ppm.

BWT advertises the pouch as lasting 2 months, and I find this to be true. After 2 months I start to see the GH of the water in the tank rise to 5 or more drops.

My understanding is that I am on the edge of what is acceptable hardness, so I descale my machine (Profitec Pro 500) annually. I also purge about 4 oz. of hot water from its steam boiler after each use of the steam wand.

I love the taste of my tap water (and also the espresso it produces), and I find it preferable to bottled water. I like the convenience of an in-tank pouch, and I'd like to avoid using a pitcher, using bottled water, or making my own water if at all possible.

I refill my reservoir after the last use of the machine each day, so the pouch has the time overnight to soften the water. I don't find the 10 hours or so that the pouch needs to work to be an issue for me.

I got started with BWT pouches because they are sold by my machine's dealer (WLL). But I'm considering trying Oscar pouches which might have a longer life and therefore a lower expense. My PP 500 also came with a hose that can be used with an in-line in-tank filter (maybe like this?) that might be an option. Would either the Oscar or a in-line resin filter reduce hardness more than the BWT without introducing any other issues?

Here is my water utility's quality report (full report here):

I'm pretty much of a newbie when it comes to water, so any advice would be appreciated.

Thanks for the help!

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#2: Post by homeburrero »

mycatsnameisbernie wrote:But I'm considering trying Oscar pouches which might have a longer life and therefore a lower expense.
They both come in different sizes, but it is true that the Bilt/Oscar/Rocket pouches are much higher capacity. The BWT Large capacity is supposedly around 200 liters at 10 °dKH (about 35.6 grams CaCO3 equivalent) and the small Oscar 90 is about 450 liters at 9 French degrees (40.5 grams CaCO3 equivalent).

They use very different softening resins. The BWT Bestsave uses a weak acid cation (WAC) resin that exchanges hydrogen ions for calcium and magnesium, and is also partly loaded with magnesium so that it exchanges some magnesium for calcium. ** The released hydrogen ion is acidic and reacts with the bicarbonate buffer. Result is lower bicarbonate, lower calcium, and lower pH, all three of which work to reduce limescale risk.

The Bilt/Oscar/Rocket is a conventional strong acid cation (SAC) resin that exchanges sodium ions for calcium and magnesium. It reduces hardness but does not reduce alkalinity and does not acidify the water. This is preferable where you might have concerns about corrosion due to low alkalinity and/or chloride ion in the water.

Your water has pretty good alklainity and reasonably low chloride so I think you can get by with either of these. One advantage of the BWT bestsave is that it does contain some activated charcoal that should help with chlorine, off-tastes, and odors. The Bilt filters don't have that, so with those you want to put charcoal filtered water into your reservoir (If you have refrigerator filtered water that would work.)

You could probably expect more reliable and predictable softening using one of the reservoir hose-end filters with a conventional SAC resin but I don't know much about that Ascaso filter.

** Edit addition -- Some vendors do say that the bestsave pouches use the BWT patented magnesium resin, but I can't find that claim on any of the current or online information. So I struck out that statement since may or may not be true.
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