Thanks for your answer Tweaking!
I’ve also read about that water temperature matters in this case, too cold water just goes straight through the body.
Starting 01/05/2009: BPEL: 15.5 cm (6.1 inches) MSEG: 12.5 cm (4.9 inches)
back then: BPEL: 17.5 cm (6.9 inches) MSEG: 13 cm (5.1 inches)
Now: BPEL: 16.5 cm (6.5 inches) MSEG: 12.7 cm (5.0 inches)