If you own fish or other aquatic animals, one piece of equipment that you’ll have to buy, regardless of all other factors, is a filter for your home aquarium. Since tanks are both dense and enclosed, it’s easy for the water inside to become polluted, especially if it doesn’t cycle. Filters constantly work to clean the water in the aquarium of debris and toxic substances and biowastes like nitrates and ammonia. They also aerate the tank’s water so that your fish can breathe better. Basically, filters are immensely beneficial to the health and well-being of your fish. They also save you the time and effort of having to manually scoop out your fish and clean the tank once a week. This also saves your fish the stress of being suddenly removed from their home into a new environment. There are quite a few different types of filters that vary depending on the size of your tank and the type of fauna you own, so there’s sure to be just the right option for you and your pets’ needs. If you’re looking for a new filter for your current fish tank or are planning to buy some new aquatic pets, here are a few aquarium filters we recommend.
What to Consider in Aquarium Filters
Here are a few things to think about before buying an aquarium filter:
- Tank Size: It’s important to know how large your tank is before you pick a filter for it. Specifically, you’ll want to know how many gallons of water your tank is designed to hold. If you don’t know the exact amount, you should at least have a good idea of the size range it falls into. Any filter you buy will list the tank size it should be used in (5-gallon, 10-to-20 gallon, etc.). You want to be absolutely sure you buy the right filter for your tank’s size to ensure it works properly. If you stick a 10-to-20-gallon filter in a 30-gallon aquarium, for instance, it’s not going to fully clean the tank, and you’ll wind up with dirty water despite the filter. If you stick a too large and too powerful a filter in too small of a tank, it can make the water current too strong for your fish.
- Type: Choosing the correct type of filter may seem like a tricky challenge for new aquarium owners. The main types of aquarium filters you’ll find are sponge, internal (submersible), undergravel, HOB, canister, and sump (wet/dry) filters. Sponge filters are inexpensive and easy to use, but they also require weekly water changes and maintenance to prevent clogging. Internal filters go right in the water and are generally compact and efficient. Undergravel filters are plastic mesh screens on the bottom of the tank, largely hidden from view, inexpensive, and easy to install. HOB filters are more complex, pricey, and noisy, but they also provide high-level filtration. Canister filters are powerful, effective, and customizable, though they’re expensive and high maintenance. Sump filters are low maintenance and quiet, but they’re also bulky, may require special modifications to install, and often need to be paired with another type of filter. Generally, for small aquariums (10-gallon or less), you’ll probably want to spring for a sponge, undergravel, or internal filter. Internal filters are an especially good choice for beta fish, shrimp, and plants in small tanks. You’ll want to avoid an undergravel filter if you have a lot of bottom-feeder species, as they may get stuck underneath them. HOB filters will work in just about any type of aquarium, as long as you find one that’s the proper size for your tank. Canisters are best suited to larger tanks (at least 20 gallons in size, though ideally 50 gallons or more) and aquariums with a high number of fish. Sump filters are ideal for marine and reef tanks of all sizes or aquariums that have been professionally aquascaped.
- Filtration Type: There are three main filter types: mechanical, chemical, and biological. Mechanical filters automatically collect and remove debris through some sort of fine mesh or cotton filter pad. Just about any type of filter you buy will have a mechanical filtering function. Chemical filters use filter media, chips of resin or activated carbon in a bag or cartridge or basket inside the filtration system, which attract and soak up toxins from the water. They’re the second most common type. Biological filters take in ammonia and nitrites in the water and convert them to a nontoxic form to help prevent your fish from getting sick. Biological filters are the least common type. Depending on the type of filter, it may use only one of these stages to clean your aquarium water, while others use a combo or two or all three.
Best All-Around: AquaClear Fish Tank Filter
If you’re unsure of which type of filter you want or is best for your home aquarium, this model is a good choice. It’s available in five different sizes, each suitable for a range of sizes, so you can find one that is suitable for a tank with a capacity anywhere between five and 110 gallons. It’s suitable for fresh and saltwater tanks and offers all three types of filtration: mechanical, chemical, and biological, thanks to the foam, carbon filter, and cycle guard features. These multistage features work together to provide premium filtration and superior water quality. Installation is quick and easy, and the entire system has an energy-efficient pump to prevent ramping up your electricity bill each month. It also offers better contact time with the filter media than many comparable devices, as well as seven times the filtration volume while still providing gentle water flow. For optimal results and effectiveness, be sure to clean the filter every two weeks. A power cord comes included with the filter and all its necessary interior pieces.
AquaClear, Fish Tank Filter, 20 to 50 Gallons, 50v, A610
A comprehensive filtering device that offers all three types of filtration and is suitable for both fresh and saltwater.
Best Triple Filtration: Aqua-Tech Power Aquarium Filter
An aquarium filter that offers an advanced triple filtration system for easier and more effective water maintenance. As the water flows through the filter, it takes part in a three-step process to weed out all sorts of impurities. First, the filter cartridge, aided by its molded and ribbed back, screens out dirt and other debris. Second, the advanced carbon inside filter cartridge weeds out odors, discolorations, and impurities; be sure to replace this cartridge monthly as the carbon becomes less effective over time. Lastly, the biotech biological grid eliminates toxic ammonia and nitrite. The biological grid comes with the power filter and has an anti-clog design for more effective straining. This whole system works together to ensure maximum water to carbon contact for cleaner and fresher aquarium water. The filter is available in three different sizes: a 5-to-15-gallon model, a 20 to 40-gallon model, and a 30-to-60-gallon model.
Aqua-Tech Power Aquarium Filter, 30 to 60-Gallon Aquariums
An aquarium filter that offers an advanced triple filtration system for maximum water to carbon contact.
Best Sponge Filter: Aquarium Technology, Inc. Hydro-Sponge Filter
If you’re looking for the cost efficiency and ease of use provided by a sponge filter, consider this model as either a standalone for your aquarium or to supplement an already-existing filter. This sponge filter is made from high-quality patented sponge foam to provide the highest mechanical debris and biocapacity filtering. It traps waste particles, cleaning the water without worrying about trapping baby or small fish. This model has a heavy base with a raised bottom, which allows it to be used vertically or horizontally. The 1-inch diameter lift tube provides greater water flow and the use of a powerhead without needing an adapter. This device comes in five different sizes for small, medium, and large tanks. Best of all, it’s easy to clean. Simply rinse and squeeze in used aquarium water (not tap water).
Lustar – Hydro-Sponge V Filter for Aquariums up to 125 Gallons
An easy-to-use-and-clean sponge filter that can be placed horizontally or vertically.
Best for Small Tanks: Tetra Aquarium Filter
Some species of fish tend to thrive better alone or in small groups, which means that they don’t require very large tanks or aquariums. This includes, but is not limited to, bettas, tetras, guppies, and other similar fish. If you have a smaller capacity aquarium, whether due to owning these types of fish or a lack of extra space in your home or any other reason, consider this filter. It’s designed specifically with extra-small (1-to-4-gallon) tanks in mind. This compact model clips onto the tank wall and can easily be tucked away or hidden to save space. Despite its small size, this filter is extremely effective. The cartridge floss catches debris, dirt, and waste, while the carbon works to remove odors and discolorations. It uses small, quiet, internal filter cartridges, which adjust easily to high and low water levels alike. You receive everything you need with your purchase, the hinged lid, tank clip, internal filter, and filter cartridge. If you own a slightly larger tank, there are three other size options available for purchase; one for up to 10 gallons, one for up to 30 gallons, and one for up to 40 gallons.
Tetra Aquarium Filter (AQ-68056),Up to 4-Gallons
A small but powerful aquarium filter designed for use in nano tanks.
Best Undergravel Filter: PENN-PLAX Premium Undergravel Aquarium Filter
This classic and inexpensive but effective undergravel filter is both easy to disguise at the bottom of an aquarium and easy to install. This premium model is air driven and paired with an air pump (sold separately), it helps keep your aquarium water especially clear and neat. As air gets pushed through the air stones and through the lift tubes, the water is softly and gently suctioned through the gravel and filter plates and passes through the activated carbon cartridges. This not only cleans the water biologically, chemically, and physically, but also aerates your fish tank. It also encourages useful, beneficial anaerobic bacteria to settle within the gravel and filter plates, a type of bacteria that makes it easier to filter and reduce nitrate. This model is suitable for 15-to-20-gallon tanks. You’ll receive filter plates, air stones, adjustable lift tubes, and filter cartridges with your purchase.
PENN-PLAX Clear-Free Premium Under Gravel Aquarium Filter (UGF) – Freshwater and Saltwater Safe – Suitable for 15 – 20 Gallon Tanks
A classic undergravel filter that is powerful, efficient, and easy to use and install.