The aquarium filter is undisputedly the single most essential piece of equipment for your aquarium – it saves you a lot of work in terms of maintenance by automating the cleaning process, so what is the best type of filtration for an aquarium?
Without a filter, an aquarium can get dirty really fast. Not only does it look unpleasant (which defeats the main purpose of having an aquarium), but it also can kill your fish through high levels of ammonia and bacteria.
Since it is such a vital component, you should select your aquarium filter carefully. We’ll help you get the best aquarium filters for your fish tank by telling you what to look for, as well as by offering some of our handpicked products.
Let’s get started.
Selecting the Best Fish Tank Filters: Factors to Consider
Filtration Type
There are three main types of filtration when it comes to aquariums: mechanical, chemical, and biological.
Mechanical filtration is the removal of waste particles by trapping them in porous surfaces.
Biological filtration is the process of converting ammonia into nitrates with the help of nitrifying bacteria.
Chemical filtration is the purification of water through various chemicals such as activated charcoal.
Filters you should look for should have mechanical and biological filtrations, while chemical filtration is optional.
Internal or External
The filter can be inside the water (internal), or it can be outside (external). Many prefer external filters as it does not take up space inside the tank or mess with its aesthetics.
External filters are also easier to clean and service.
Internal filters do have one advantage though: in case the flow of water is disrupted, such as due to a power outage, the nitrifying bacteria can survive for some time because the water provides it with some oxygen. In an external filter the bacteria will be completely starved of oxygen and food.
Type of Filter
There are numerous types of filters out there; you can pick and choose based on your specific needs and budget.
Canister Filter – Canister filters for aquariums are the most professional filters you can get for your fish tank. Their power is unmatched, they offer effective filtration, and they work really quietly. All of that comes with a hefty price tag of course. Also, they are a bit complicated, hard to maintain, and can break down sometimes.
Sponge Filters – Aquarium sponge filters are some of the commonest and cheapest filters you can get. It is just a simple design, with an air pump creating a flow of water through a sponge, which traps organic waste and creates a home for nitrifying bacteria. Because the design is so simple, not much can go wrong with it – even if it does, it is easy to fix and cheap to replace.
Hang on Back Aquarium Filters – The hang-on-back (HOB) filter is another commonly used variety that also costs only a few bucks. As its name suggests, it is meant to hang on the side of your tank, drawing water from the tank, filtering it, and releasing it like a waterfall. It is a bit noisy due to the splashing water.
Fluidized Bed Aquarium Filters – This filter contains fine sand media that is always churned by moving water, resulting in an enormous amount of surface area for bacteria to grow. Therefore, it’s highly efficient at converting ammonia to nitrate. Get this if your aquarium is likely to produce a ton of organic waste.
Type of Fish You Have
It’s a well-known fact that some fish produce more waste than others.
The goldfish is a notorious example – they are considered waste-producing machines. The best fish tank filters for goldfish should be able to handle the high waste output – we recommend getting a canister or fluidized bed filter.
Other animals such as turtles are also similarly guilty.
You should also look at the bioload of your tank, which refers to the amount of waste-producing creatures in the tank. A small tank with a high bioload is going to need a powerful filter.
Power/ Water Flow
Make sure the filter you get is sufficient for your tank. The rule of thumb is for the filter to be able to go through 4 times the tank volume in 1 hour. If you have a high bioload, you should go for something even more powerful.
A highly powerful water flow is not desirable either, as it can be stressful to some fish or may even injure them.
What are the Best Aquarium Filters
1. Tetra Whisper IQ Power Filter with Stay Clean Technology
This hang on back aquarium filter from Tetra is cheap and does a good job with small to medium-sized tanks.
It is purported to maintain healthy pH levels in the tank with its Stay Clean Technology, which is vital for aquatic life.
The motor starts with no priming and is designed to be quiet with a sound barrier and vibration-damping technology, but the flow of water from the outlet is still noisy.
The filter has a tendency to spring a leak, which is not good for the water level.
The company advises you to replace the filter cartridges monthly. First off, this means a lot more bucks out of your pocket. Secondly, every time you replace the filter media, you are also taking away the colony of beneficial bacteria that took time to develop.
What Our Testers Say:
We found no leaks, thankfully. The motor is somewhat quiet, but you can’t escape from the sound of splashing water. The only remedy would be to increase the water level.
What We Like
- Maintains healthy pH levels
- Affordable
- Motor starts with no priming
- Quiet motor
What We Don’t like
- Waterfall is still noisy
- Has a tendency to leak
- Requires monthly cartridge refill
2. Fluval FX6 High Performance Aquarium Filter, Canister Filter for Aquariums up to 400 Gal.
The Fluval FX6 is one of the best canister filters for aquariums. It is a powerhouse filter for tanks sized from 175 to 400 gallons, with up to 3500 L per hour!
It is not just brute force either; it comes with a smart microchip that allows for features such as self-priming and auto starting. It also auto evacuates trapped air every 12 hours.
The 2 outflow nozzles mean you can customize the water flow in your tank. The drainage pipe makes it easy to do routine water changes.
Being one of the best aquarium canister filters out there, it doesn’t exactly come cheap.
Many say the hose could be of better quality. Moreover, the whole thing is a bit difficult to set up and the instructions aren’t that much of a help either.
What Our Testers Say:
Once you set it up properly, it works likes a monster. It automates a lot of stuff, and you can put inside a lot of filter media – it’s highly customizable. They are great filters for 100 gallon aquarium and upwards. Our verdict: value for money
What We Like
- Heavy duty filter; 3500 L per hour
- Embedded with smart microchip 2 output nozzles
- Easy water changes · Includes all 3 types of filtration
What We Don’t like
- Hefty price tag
- Somewhat difficult to set up
- Hose quality could be better
3. MarineLand Penguin Power Filter
Another cheap but good enough hang on back aquarium filter, this time from MarineLand. It comprises all 3 types of filtration; it even has chemical filtration via activated carbon.
It boasts of a patented biowheel filter that offers 50% more surface area for excellent biological filtration.
You can use a built-in strainer to adjust the water flow; this can help make it quieter.
It needs to be primed manually, but it’s not a big deal since you only do it once in a while. But the monthly cartridge replacement is something that can raise your eyebrows.
Moreover, many people complain that the impeller breaks down easily, and it is not that cheap to replace.
What Our Testers Say:
Quick and easy setup, with many convenient features. It is somewhat bulky though, and can take up a lot of space in your tank
What We Like
- Patented biowheel filter
- All 3 types of filtration
- Water flow can be adjusted
- Easy to set up
What We Don’t like
- Needs to be primed manually
- Requires you to buy cartridges monthly from manufacturer
- Impeller tends to break down
4. Fluval U Series Underwater Filter, Freshwater and Saltwater Aquarium Filter
This Fluval internal aquarium filter offers all 3 types of filtration: mechanical, chemical, and biological.
Being inside the water with no air pump, you can expect this filter to be extremely quiet.
It is customizable as to where you want the water to flow out from; your options are top, which offers the best circulation and oxygenation, bottom, which provides deep-water agitation, and middle, which gives you a gentle spray to avoid strong flows.
You can also install it either vertically or horizontally; however, the horizontal orientation nullifies the water outflow options we just talked about.
Being an internal filter, it does take some valuable space inside the tank. And it is not a highly powerful filter, even for its rated volume.
Also, watch out for the monthly filter cartridge replacement costs that the manufacturer subtly imposes on the product.
What Our Testers Say:
As expected, this is not a highly powerful filter, so not for any serious aquariums. It is extremely quiet though, and the outflow options are nice.
What We Like
- All 3 types of filtration
- 3 water output options
- Very quiet operation
- Quick and easy filter cartridge removal
What We Don’t like
- Filter not that powerful
- Takes a fair amount of space inside tank
- Monthly filter replacements take money out of your pockets
5. AQUANEAT Aquarium 3 Pack Bio Sponge Filter Breeding Fry Betta Shrimp Nano Fish Tank
Like most sponge filters for aquariums, this one costs only a few bucks and is very easy to set up (air pump is not included though).
One thing we like about it is that it looks sleek and elegant, with a black color that allows it to fade into the background.
And with detachable parts, it is easy to clean too; just don’t use tap water as the chlorine can kill off the beneficial bacteria – use water from the tank itself.
The cherry on top? It doesn’t need filter media replacements; you only have to replace the sponge once every 3-6 months or so. This makes it a very cost-effective filter.
The only issue is it’s a bit too buoyant for our liking; you may have to clamp it down or put some weight on it.
What Our Testers Say:
It works well enough for small tanks, and the buoyancy issue is not a big deal. Our verdict: something simple and cheap, but still value for money.
What We Like
- Cheap and easy to set up
- Detachable parts easy to clean
- Looks sleek
- Low maintenance costs
What We Don’t like
- Air pump not included
- A little too buoyant
