AquaClears are hands down the best hang-on-back (HOB) filters on the market. They have much more flow, much more media, and you can easily customize the media. In addition, their media is reusable so you don’t have to pay for overpriced media cartridges every month. This alone makes a massive difference because they will pay for themselves over time just in the savings on filter cartridges.
Flow
The flow on the Aquaclear is much more than any other HOBs and even more than most canisters. the AquaClear 110 has 500gph of flow. There are only a few canisters that have more flow than this. Most have significantly less than this.
Media Capacity
The media capacity is much higher with the AquaClears. If you lay out the media from any other HOB next to the media for an AquaClear it is a joke that the others think they are good filters. There is simply no comparison.
Customizable Media
You can easily swap out the media to fit any needs. They come with a big foam block, a bag of carbon, and a bag of Biomedia. You shouldn’t need to use the carbon. You can simply leave it out or you can add Purigen, a bag of crushed coral, peat granules, more biomedia, or almost anything else.
Reusable Media
The media that comes with the AquaClear can be used over and over for years (except the carbon of course). The foam block can simply be rinsed clean over and over. I do not recommend using tank water for this. This block is very good and can trap lots and lots of debris so simply rinsing it in tank water isn’t enough. You need strong flow from tap water to really get all that gunk out. Squeeze and rinse under tap water until the water comes out clear. The biomedia is like any good biomedia in that you may need to lightly rinse visible debris off, but you can use it for years.
Cons
There are only two cons to these filters. One is the intake strainer which is really bad. Do not use an AquaClear with just their intake strainer, it is too small and all that flow through such a small area is strong enough to grab hold of healthy fish and get them stuck to the intake or even pull them through. I have even seen snails pulled out of their shells because they were cruising down the intake tube and then hit the strainer. Do not use them without an additional intake cover. There are sponge filter options out there, but these look ugly in the tank and just create an additional thing to clean (that you have to go in to the tank to get). Instead, make your own intake strainer with black needlepoint canvas plastic mesh.
The other problem is the little piece of plastic that holds the filter off the back of the tank. It used to be fine, but some idiot at the company thought it would be good to save $0.01 in manufacturing cost to cut half the plastic off this piece so now it has little arms that aren’t strong enough to hold the weight of the filter. The little arms bend and the piece will pop off because of the new angle. Sometimes super gluing the piece in place is enough, but sometimes you need to prop the filter off the tank with a piece of wood, plastic, PVC pipe, etc.
Both of these issues are simple and could be completely avoided with effectively no additional manufacturing or retail cost, but it is what it is (and these filters are more than worth the hassle of these two small issues.
Summary
Don’t hesitate to buy these. If you need a HOB filter, the AquaClear is by far the best option.