why does the charcoal canteen lose durability when collecting clean water?

[Snazzy Salamander]

I think the idea of the charcoal canteen is awesome and being able to filter dirty water so you don't have to go around collecting fresh water is great, and I get that it having a durability bar makes sense even if I don't really like it that much but the problem I have comes when the durability goes down even when you collect clean water. The bigger upside on the canteen for me is that it carries more water than the other two but when collecting clean water wears down the durability it eventually gets to a point where you might want to refill your canteen cause there is some dew drops around and you have room but it breaks the durability and now not only can you not fill it, you cant even drink from it until it gets repaired. I don't know if this is intended or not but either way I think It should be changed because It doesn't make sense that clean water would use durability on a filter.

[Dtormala83]

Perhaps the reason that it loses durability when  collecting water caused well Charcoal, You think about it actually does dissolve over time when it gets wet so it really does make sense.