First, I'll start out with the facts. The 2213 pumps up to 116gph and has complete three stage filtration. It comes with all the filter media including EHFIMECH mechanical filtration media, EHFISUBSTRAT PRO biological media, and coarse, fine, and carbon pads. It also comes with all tubing and, the best feature, double disconnect valves. These valves work great and make up for the fact that the Eheim 2213 has no auto-start feature (more on this later). Everything is high quality and you can tell a lot of thought and design went into each piece, which is typical Eheim style.
Setting up the filter is fairly easy, although the instruction manual is not very helpful. Pictures and intuition are paramount and whatever you do, don't cut the tubing before you're absolutely sure it'll reach where you want it to go! The Eheim 2213 is different from the larger 2217 in that inside the canister it has a media basket. All the media is placed inside instead of just being dumped into the canister in layers. However, the benefits of this are few and far between and I think the designers should have put some more thought into the way the top of the basket twists on. When you go to clean the filter out, trying to twist on or off a slippery, dirty, slimy piece of plastic with absolutely no leverage besides a flimsy handle to lift the basket out is not easy.
Once you get all the media set up the hardest part is actually starting the filter for the first time. Since there is no auto-start feature, you're forced to find a way to create a siphon (usually by sucking on the end of the tube, which is never pleasant). The good news is, once you fill it up, you never have to do it again. Just remember to shut the double valves before you shut off the filter and the tubes will stay filled. That way, you just plug it in, start it up, and open up the valves and you're ready to go again.
In terms of effectiveness, it is extremely efficient (only 8W, compared to the 2217's 20W or 30W+ for those cheaper canister filters). The flow is very low, but this is apparently why it is so efficient, both in terms of power and removing nitrates and ammonia from the water. Longer contact time with the media means more wastes are absorbed by the bacteria. However, in terms of mechanical effectiveness, the flow rate doesn't really work. I had it on a 29 gallon planted aquarium with a heavy fish load and it couldn't keep up. Debris and mulm started to accumulate on the bottom of my tank. I'm guessing that with a non-planted tank and with a regular fish load, it may be able to handle a 66 gallon tank. But in terms of usage on a planted tank, I'd say the maximum effective capacity is 30 gallons. It works great on my 20 gallon tank now, and an Eheim 2217 does the job perfectly on the 29 gallon aquarium.
Overall, the Eheim 2213 is a great little filter. Aside from being a bit underpowered for medium or larger planted tanks, its design is top notch. And luckily, Eheim offers a full range of (more powerful) classic line canister filters that larger planted aquarium enthusiasts can choose from. I give the Eheim 2213 four out of five fish:
Buy an Eheim Classic Canister 2213 from Drs. Foster & Smith now.