A strange problem with BWT Initium 2.5 l filter's scale

Is there anyone, who has BWT Initium 2.5 l filter and can explain me, what is going on with their scale?

When I fill it with water and wait until it filters out to exactly 1000 ml mark and then pour this water to another vessel with scale, it turns out, that I actually have 700-800 ml. By analogy, when I filter exactly 1500 ml on BWT Initium scale and pour that water out, I can get 1,2 liter at most.

Is there anyone, who could explain me this magic?

I've been using many filters before BWT Initium and when filter scale showed 1500 ml, I could pour 1,5 liter kettle to the top. This is my first product, that has so strange scale.

Best Answer

Reply just received from pot's producer. In case someone would be interested about "the magic":

The scale with 2,5l just applies to the empty jug without funnel and cartridge. So the funnel with cartridge inside displaces the water in the jug. I just tried this out with my own Initium jug.

If you fill in 1000ml it´s the same amount of water, but it will be e little bit more at the scale.

I know, this is a little bit confusing, because the measurement can be read as the amount of filtered water. I´m very sorry for that. But I guess this explains the “magic” in this case.