Hi
The pole does not fill with water, there is a small length of hose in the top section, with a fitting at the bottom.
The fitting is made of stainless steel, it never sees daylight as it were so it will last a long time before wear.
the fitting is around £5 to replace.
as regards weight we do not know for sure, the 18ft pole i have showed a preview of, is a sample, that weighs 1000grm
We are having made more clamps for the other poles this week, when all assembled we will know the correct weights
Steven.