Why would you run a water line directly into the tubing on your canister filter? I don't recommend using that method as there is always the possibility of cross contamination of your potable water system.
Why not just run a separate line to the tank?
Eheim Pimpette #270
Eheim Pro II 2028; Classics Series -2215, 2217, 2260, 2262; Pro 2229 Wet/Dry