I have the Eheim Classic 2217 running now for about 24 hours so far so good!
The flow is quite strong in my 38 gallon but I played around with the spray bar and positioned it so that it is pushing across the waterline. Now the fish don't seem to mind as much (before the flow was pushing out/downwards at 45 degrees and the fish were getting stressed being pushed around in the tank).
This is my first canister filter so I have one question regarding the filter noise level. Is it normal to hear a constant low pitch hum?
It is by no means loud but is definitely audible (it sounds like an air pump if you know what I mean). I have tried to fully empty the canister and re-prime by filling the canister with water suctioned from the intake as per the instructions but it still sounds the same. I am pretty sure I primed it correctly as there are no visible bubbles coming out from the outtake.
Please if you have any experience with canisters or especially Eheims, I would appreciate your feedback on the expected noise levels.