BRITA Jug and PH... interesting

Well here's what I encountered. I decided to check the PH of the water I am using to water my babies with and it is a bit higher than I'd want it to be - around 7,5..

So checked my tap water and the level was better - around 6,5 - 7

Then I tested the same tap water, but filtered through BRITA jug and guess what - 5.5 - 6...

Anyone had any experience and an explanation why this happens?
And also, should I change the water I am using as I am in the middle of this grow now...?

Heey, I've found a way to lower PH without any additives and no one gives a crab? Or is it so obvious and generally known that no one bothers to comment.. That's 7ph to 5 just with a regular filtering jug...

I really want somebody just to explain to me why it happens actually

Pure water has a neutral value of 7.0. Lower values indicate that a liquid is acid (an acid), higher values that it is alkaline (an alkali).

BRITA purposely decreases water hardness to improve the taste of drinking water. As a result, the pH value of BRITA filtered water tends to be in the slightly acid range.

The actual pH value of your BRITA water can depend on a number of factors, e.g., the current pH value of your water, the freshness of your filter, etc. However, most websites that have posted values for water purified by BRITA indicated pH values between 5.0 and 7.0.

from 2008:
https://www.rollitup.org/hydroponics-aeroponics/51955-brita-water-filter-ppm-ph.html