I am working on a EK reservour and I do not know whet would be best thing to do. So here are 2 versions of reservoir.

Material is acrylic tube 50mm.
Black POM acetal for top and bottom.
Sealing between tube and POM with O-ring.

1nd version:
option 1:




option 2:


2nd version:




Please let me know what do you think and which ne do you prefer and why. What would you add etc...

Thanks!