Digital BW, The Print

I am about to ad ink for the first time to the CFS on my 1270.
Was wondering if it will make any difference on how I do that?

Thought about leaving the jar that has the tube sucking from it now 
in place and carefully pouring the new ink into that jar...

OR

Removing the tube and cap from the jar in place, pouring what ink 
remains into the new jar and putting tube and cap on New jar.

Little tiny conservative part of me (;-) is concerned that I'll lose 
some vacuumy thing going on with the tube that's already sucking ink 
from the jar in place!?

Thanks,
Cleavis