This is an excerpt from one of the many top Canister Filters breakdowns online:
Top 6 Canister Filters
From Shirlie Sharpe,
Your Guide to Freshwater Aquariums
1. Eheim Canister Filters
View Full-SizeBoasting a high throughput rate and durability, the Eheim is the quietest canister on the market. I like the compact design and easy to handle latches. My only complaint is the lack of self-priming, a common problem in canister filers. However, priming is vastly improved in the Ecco and Pro II series. Although pricier than other brands, I've found that over time Eheim out performs them.
2. Magnum
View Full-SizeMagnum balances price with some of the best features in a canister. It is self-priming, quiet, and offers convertible filtration modes, including the option of adding a matching Biowheel system. The clear canister makes it easy to see the condition of the filter. Optional gravel cleaner is a nice perk to an all around great package.
3. Fluval
Fluval produces one of the most economic, yet efficient, multi-media filters available. Learning a lesson from their older models that were too tall and unwieldy to service, the redesigned models are compact, and sport larger latches similar to the Eheim products. Priming is still a headache, and they tend to be noisy if not properly filled. In spite of that, you can't go wrong with a Fluval.
4. Proquatics
If it weren't for the lack of performance data, this filter might rival Magnum and Fluval. The unit is built with the same top-notch features, such as self-priming, easily removed media basket, large easy to release latches, and top mounted swiveling flow controls. So far I've been very impressed with its performance.
Vendor's Site
5. Rena FilStar Canister Filter
Although less well known that other canisters, the FilStar has many of the same features. The self locking water shutoff system is a nice touch, and the price is very competitive with other canister filters of the same size.
6. ViaAqua
ViaAqua has moved beyond their popular powerheads and pumps and is offering a line of canister filters. Recessed handles, large media baskets, shut-off valves, in addition to low prices, make them highly competative with other canister filters.
For the most part, all of the info I've seen is just according to what the individual buyer prefers.
FOR ME, I've used Eheim, Fluval, a ViaAqua ( I think that's what it was ) & I settled over the years on Magnum 350's b/c they were self priming & the price was pretty good for what you got.
Now the downside that I've had with all of the Canister Filters that I've ever owned was when they had problems they leaked & water damage when they do,....b/c of the tubes from the Canister to the Aquarium.
Also if you had more than one filter in a confined space, it could/can get a little confusing & not as easy to service over time & I've learned that it's best to make the upkeep of your aquarium as simple & easy as possible, so you'll continue to do them in a timely manner.
I have almost all HOT Magnums on my tanks for that very reason.
JMOpinion
LJx