In the world of fishkeeping there are really only two main types of fish tank filtration that people use: power or ‘hang on the back’ filters and canister filters. Sure some advanced aquarists and reefers use sumps and protein skimmers, and there are the old ‘under-the-gravel’ filters and sponge filters, but the vast majority either use a power filter or a canister filter.
Today I thought I would write an article comparing the two just to get some insight into the pros and cons of each type. Hopefully, this will shed some light on the subject in case you are on the fence about which type to purchase.
When it comes to hang on the back filters one of the advantages of these filters is that they are relatively low cost and they’re pretty easy to maintain. The other thing I like about them is they tend to be pretty reliable. I haven’t had too many issues with any of my hang on the back filters. I plug them in and they just run.
Another advantage of a hang on the back filter when I compare it to a canister filter is there’s almost no risk of flooding your floor. If it goes down, usually the water just stops flowing but it stays contained in a tank and in the filter.
Now a disadvantage of hang on the back filters is they can be a little bit noisy depending on the brand that you purchase.
Let’s take a look at a canister filter. One of the advantages of canister filters, in general, is usually they go under a tank not on the back of the tank and because of that you can move a tank closer to the wall. You don’t have this large, bulky, hang on the back filter in between the wall and the tank. That makes the entire filtration system less visible. The canister filter also does a better job, in my opinion, of keeping your tank water clear.
Another advantage with a canister filter is that the intake and the outtake are a little bit further apart so you can put them on opposite ends of the tank. That creates a lot more water flow. A hang on the back filter just dumps the water in through the top at the same spot as the water intake. Water flows from front to back in the area where the hang on the back filter is, but on a canister filter, you can actually get the flow to go side to side. That will relieve some of the dead spots that you might find in your filtration.
Often there’s going to be more room for media in a canister filter for beneficial microbes compared to a hang on the back. Another advantage is it might be a little bit easier with a canister filter to use different types of media. You can use some bio ball material and filter floss. You can use carbon. You can put the bio balls or whatever you use for bio media in a filter media bag so it’s not just kind of loose. It makes it a little bit easier to maintain the filter.
I think one of the primary advantages to canister filters is how quiet they are. Even a small filter makes zero noise and I have a tank right in my living room where I don’t want to hear water running. It’s really awesome at making just about zero noise in the living room which is pretty cool.
For some larger canister filters, it might be possible to hook up an inline UV light, something that would be a lot harder to do on a hang on the back filter. The canister filter really does lend itself well to having an inline UV light sterilizer.
What are some disadvantages of a canister filter? Well, I think one thing is the top and the bottom have to seal tightly together and if they don’t seal tightly, water can leak. It’s not ideal for carpeted areas.
Another thing is maintenance. I hate maintaining that thing. I just dread it. It’s definitely not something I enjoy. A hang on the back you just pull the media out. It takes two seconds. With a canister filter, you’ve got to undo all the hoses, you have to unseal it, you have to break it down, you have to pull the media out and then put it back. Now some canister filters make that job a lot easier it’s just not nearly as easy as a hang on the back filter.
Another major downside is cost. Canister filters for that additional flow, for the additional surface area, for the quietness that it has you’re going to pay more money. You can easily spend three, four, five hundred dollars on a canister filter and that can get expensive. There are some decent ones under $100 though.
Another disadvantage may be if a hose goes on a canister filter or a seal breaks you could have water on the ground. It’s not a guarantee that’s gonna happen. It’s unusual that it would happen, but with a hang on the back filter, it’s really not going to happen. If a hang on the back filter has issues, 99 times out of 100 the water is going to stay contained in either the filter or the tank and not on the floor.
With a canister filter, because that canister filter is often under the tank if a problem happens with a seal you might wind up with water somewhere else. Both of them share one inherent problem, and that is, if the power goes out they may not restart when the power comes back on.
So which one do I prefer?
It’s a tough choice. I think it depends upon the needs that you have for your tank. If this is a tank that’s going to be in a living room or a bedroom, I want to have as quiet a filter as I can possibly can, so a canister filter would be the way to go. If your living room or bedroom is carpeted, I would think twice.
If it’s just a tank with a lot of other tanks maybe in a basement or in a room that’s not going to be an area where there’s gonna be a lot of conversation or it’s not going to be a quiet area, a hang on the back filter might be a little bit easier.
Also, the larger the tank the more sense it makes to probably to have a canister filter. If you’ve got maybe a 90 gallon fish tank and above, canister filters are gonna get you a lot more flow, have a lot more power, have a lot more surface area, and it’s probably going to make more sense than trying to put on 2 or 3 hanging on the back filters along the back of that tank.
Those are just some thoughts when it comes to hang on the back filters versus canister filters again it really is going to depend upon your needs and your desires. Do you have the money for a canister filter? Do you want a little bit of a cleaner look? Do you want that increased flow? Then maybe canister filters are for you. If you’re just starting out, maybe it’s going to be a lot easier to put a hang on the back filter on that tank. It’s going to be easier to maintain. It’s not gonna cost as much, especially if you don’t know how long you’re gonna be keeping the tank when you’re just getting into the hobby.
Those are just some pros and cons. I would love to hear your feedback in the comments section. Let me know what you’re struggling with. If you’ve got a preference for one over the other please share that. Share the advantages and disadvantages that you found when you use these types of filters.
Hang on The Back vs Canister Filter
|Hang On The Back||Canister|
|Cost||$15 - $55||$35 - $350|
|Noise||Medium to High|
Mostly water return noise, but if the impeller wears that can be noisy too.
|Low to None|
|Performance||Perform very well for tanks under 50 gallons||Can leak from broken seals or hose connections.|
|Media||Limited||More options for type of media. Holds more.|
|Water Flow||Low||Medium to High. Better at distributing water temperature.|
|Water Cycling||Low: 100 - 350 gallons per hour||High: 250 - 950 gallons per hour|