I have a 20 gallon take that has about 20 pounds of live rock, a couple clown fish, a few zoas, a duncan coral, and a CUC in it. For my filtration, I currently have a Penguin Power Filter with a "bio wheel" and an Aquatic life 115 protein skimmer. Both are rated up to 30 gallons. The owner of the LFS is trying to convince me that I need to upgrade to a canister filter, but I'd like a second opinion. Is a canister filter something my tank needs, or will my current filtration system do just fine for my tank? I'm attaching a couple pictures of these products, just for a little more clarification. Thanks.