[nemom109r]

Similarly, I run a homemade s/s tube with a Donaldson 5um fuel filter inline. It has a small ball valve before the filter.
I fill the stainless tube to near the brim (roughly 5 liters), let gravity do the work through the filter, and close it off again.
Haven't had to change the filter yet but will soon.

 

[nemom109r]

Perhaps a chemical reaction over time? That'd slow the flow if it is. maybe there's Chinese and Chineez.