Yes, that can also happen in relation to the hardness of the water (I don't know if this is also said in English) that is, the amount of limestone in the water, the less the limestone the higher the dilution.If cleaning ultrasonically err on the side of caution with the ilfotol, it can foam.
With distilled or demineralized water the dilution will further increase significantly.
I only use deionised water. The tap water here is nearly the hardest of the hard. But not harder than Bruce Lee.With distilled or demineralized water the dilution will further increase significantly.