16 dH to 1 dH through a Brita filter - not realistic, right?

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

#1: Post by sorenwrang »

Hi,

I recently bought a total water hardness test kit and tried it out today (similar to this: https://monarchwater.co.uk/product/tota ... -test-kit/)
The kit works by adding the test solution to your water drop by drop until the solution turns from red to green. 1 drop is equivalent to 1 dH hardness.

First I tested my tap water. The test indicated a hardness of around 16 dH (I added 16 drops before the solution turned green).

After that I tested the water from my Brita pitcher with a Brita softening filter: https://www.amazon.com/Brita-Marella-Wa ... B076NK2QM7.
The softened water turned green after just 1 drop of test solution, indicating that the hardness was now 1 dH.
Is this even possible? I've been told that the Brita filter and similar filters will reduce the hardness by around 50 percent, which made me expect a hardness of around 7-8 dH before running the test.

What's your reaction on the above?

Best regards.

RobindG

#2: Post by RobindG »

It's only the Calcium hardness that dropped, so the water won't scale. Carbonates will still be plenty, so it is not ideal tastewise. And please check your pH!

sorenwrang

#3: Post by sorenwrang » replying to RobindG »

But is it realistic that the Brita filter has removed basically ALL calcium from the water, meaning that there will be minimum or no scale building in my espresso machine? Since I have a Breville Barista Express the water is softened once more through the Breville filter in the water reservoir.

RobindG

#4: Post by RobindG »

Yes, pretty much. Calcium ions are replaced by others, mostly Hydrogen. This can make your pH of your water drop, becoming very corrosive and ruining your machine from the inside. So be very careful. Buy a pH tester.

sorenwrang

#5: Post by sorenwrang » replying to RobindG »

Very interesting! I didn't think of that. Assuming that the pH of my filtered water is too low, what's the best and easiest way to resolve that?
In general - what's the easiest and most convenient way of making sure that you have the perfect water for your espresso machine, without having to establish a mini chemistry lab?

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homeburrero
Team HB

#6: Post by homeburrero »

Those filters contain a type of softening resin called a WAC resin, also called a decarbonizing resin. WAC resins replace calcium and magnesium ions with hydrogen ions, which are in turn buffered by the bicarbonate ions ( H⁺ + HCO₃⁻ ⇋ H₂O + CO₂ ) so your bicarbonate (alkalinity) goes down along with your hardness, and the water pH goes down.

If you test again when the filter is closer to replacement time I think you will see far less effect on the hardness. These filters are not generally recommended as softeners for that reason.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

sorenwrang

#7: Post by sorenwrang » replying to homeburrero »

Can you explain how to soften the water while keeping the pH neutral?

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homeburrero
Team HB

#8: Post by homeburrero »

sorenwrang wrote:In general - what's the easiest and most convenient way of making sure that you have the perfect water for your espresso machine, without having to establish a mini chemistry lab?
See Easiest way to make rpavlis water?

And also this post for a little summary on the "rpavlis" water recipe. Robert Pavlis was a chemistry professor and espresso enthusiast who gave us tons of good advice about water, physics, and home lever machines.


sorenwrang wrote:Can you explain how to soften the water while keeping the pH neutral?
Any conventional softener, which uses a Strong Acid Cation (SAC) resin will do that. The old fashioned Italian DVA softeners do that, as well as some cartridge and generic 10" softeners. They exchange sodium ions (sometimes potassium ions) for the calcium and magnesium and don't acidify the water (and don't reduce the alkalinity). They are intended and marketed as conventional water softeners. Here's one example: https://www.chriscoffee.com/products/wa ... ion-system that has a conventional softener plus the particulate and carbon filter. Most of the BWT products are WAC resins, but the BWT Bestprotect filter is a conventional (SAC) softener.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

RobindG

#9: Post by RobindG »

I couldn't work it out, so I use Volvic now

sorenwrang

#10: Post by sorenwrang »

So to boil it down, the only ways are:
1. Make your own water using distilled water and additives.
2. Buy an SAC filter system (there are no SAC pitcher filters, right?)

Correct?