I really think people are missing the point here lol. He ALREADY has it. We know it's overkill, we know it's not needed.
To the OP. If you can and want to take it back, great--that would be ideal (for a HOB, smaller canister or FX4) If not, I am guaranteeing you can use it just fine as I mentioned above. I have used one on my 90g which is pretty much the same footprint with only 15g more of water for 4-5 years without a single issue.. with discus, community tanks and African cichlid tanks. Again, if you can return it and it's not a hassle, that's totally up to you. But if not, you can use it just fine. Hell, I've used an eheim 4+ canister beside it for the past 2 or so years, and again.. Not a single issue.