I know what you are dealing with. Since its new, i doubt the impeller is shafted (lol). I bought a 2215 used and what it needed was a new impeller. The rod that the impeller rotates around was still fine but the shaft of the impeller was worn too much to keep straight. I had the loudest filter until i got a new impeller. Almost machine gun like. Afterwards, much quieter, no rattling.
Now lets assume this is not the case. Is the filter output reduced?
-Next time, fill the canister with water and then close it.
-Then connect it to the tank and open all the quick disconnects except for the ones at the outflow of the canister.
-Unscrew the outflow quick disconnects from each other nothing should siphon back out since the valves themselves are still closed.
-Slowly open teh outflow quick disconnect valve attached to teh canister, not the one hanging from your tank.
-This is ensure the filter is primed.
-Then once water is flowing out of the filter onto your floor, close that valve and reconnect everything.
-Open all valves and turn the filter on.
IF you stilla re getting a ton of air or it becomes unprimed and you hear rattling (once again we assume the impeller is fine) What i found works but also gets water everywhere, unlock all the clamps on the filter and carefully allow the top of the filter housing to rise and eventually the air will escape from the spaces that open up as the filter top comes off from the canister itself. Sounds risky and stuff and it is. Don't do this unless you really are out of options. But i had issues priming my filter and i got fed up, did this and it ended up working haha. Basically, the siphon that is formed from the tank to the filter on the ground pulls the water into the canister and as the canister fills up it will push out the air from the tiny gaps that open as you make sure the top doesn't completely come off. once again, i advise against this but hey last resorts.