Britax filter - Is this normal?

[HuggedTrees]

Bought a filter for the first time, but after using it, beneath the filter gets left 1cm of water. No mater how much we push the filter in. This water then becomes trapped and you can’t pour it out, unless you removed the filter. Surely this isn’t normal and stagnant water is a legionnaires risk? And I don’t want 30day old water when I change the cartridge?

When you next refill the jug and empty it again, the bit of water left wont be the same bit, it will be fresh and the stuff there currently will have mixed with new water.
Surely if you are using it daily it wouldnt have a chance to become stagnant.

I was just wondering if all filter jugs are like this/it’s a general design flaw. That water is really well sealed in and yes it might mix and dilute, but for someone who is immunocompromised it’s really not good and is a risk we’ve been told about.
So I wanted to know before I returned it if this was the case with all filter jugs.

The bit that the filter clicks into projects about 1cm into this internal bit and it’s that 1cm that it’s not making a tight seal around and the water is becoming trapped.

Evening bump