What is the best freshwater aquarium filter for beginners, and why?

Setting up your first aquarium can be an exciting yet daunting experience for beginners. One of the most important pieces of equipment you’ll need is a good quality filter to keep your tank water clean and healthy for your fish. 

Choosing the right aquarium filter may seem overwhelming at first, with so many types and brands available. 

In this article, we’ll walk you through the basics of the major filter types and features to look for, and recommend some of the best options for beginner freshwater aquarists.

Why Do You Need an Aquarium Filter?

An aquarium filter serves several critical functions:

1. Removes solid waste and debris: Fish produce waste in the form of ammonia, which is toxic. Uneaten food and other organic matter also decompose, polluting the water. Filters mechanically trap particles through filter media and prevent buildup.
2. Biofiltration: Good bacteria colonize filter media and convert ammonia into less harmful nitrate. This nitrogen cycle keeps water safe for aquatic life. Filters provide surface area for beneficial bacteria.
3. Oxygenation: Filters agitate the water surface, promoting gas exchange with the air. This adds oxygen and removes carbon dioxide from the water.
4. Circulation: Filters move water around the tank for even distribution of heat, nutrients, and gases. Stagnant spots can allow waste to accumulate.
5. Chemical Filtration: Some filters have activated carbon media that adsorbs odors, discoloration, and some heavy metals. This polishes the water for maximum clarity.

For proper biofiltration, filtration capacity should be appropriately matched to the size of your tank and livestock. Beginners should start with a filter rated for at least double the tank’s volume for adequate waste removal and circulation

Types of Aquarium Filters

There are five main types of filters suitable for freshwater setups:

1. Hang-on-Back (HOB) Filters

HOB filters hang off the back of the tank with a bracket and intake tube. Water is pulled up through replaceable cartridges that trap debris and house filter media. It is then returned via a waterfall from the filter outflow.

Pros:

• Easy to install and maintain
• Adjustable water flow rate
• Greater aeration and surface turbulence
• Can supplement with additional media like activated carbon
• Relatively affordable

Cons:

• Take up tank space
• Some noise and splashing
• Limited media volume compared to canisters
• Cartridges can clog faster and need replacing

Good for:

• New hobbyists
• Small to medium-sized tanks up to 75 gallons
• Low-tech freshwater setups
• Shallow tanks with low water level

Examples: AquaClear, Tetra Whisper, and Marineland Penguin

2. Canister Filters

Canister filters are self-contained cylinders that sit below the tank. They offer large media capacity and handle heavy bioloads efficiently. The flow rate is adjustable.

Pros:

• Excellent mechanical and biological filtration
• Large media volume customization options
• Quiet operation
• Hidden equipment
• Handles heavy stocking loads
• Independent of tank water level

Cons:

• More expensive
• Requires priming and regular maintenance
• May need additional powerheads for circulation

Good for:

• Medium to large tanks over 75 gallons
• Heavily stocked aquariums
• Aquascape layouts where equipment visibility needs to be minimized

Examples: Fluval FX4/FX6, Eheim Classic, Hydor Professional

3. Undergravel Filters

Undergravel filters sit on the bottom of the substrate. Water gets pulled through the gravel via a powerhead, collecting debris for biological filtration.

Pros:

• Inexpensive
• Unobtrusive in tank
• Maintains substrate bed

Cons:

• Not ideal for planted tanks
• Limited flow rate and filtration capacity
• Hassle to clean thoroughly
• Needs strong water flow over gravel
• Outdated technology

Good for:

• Small breeding/quarantine tanks
• Fish-only systems with gravel substrate
• Tanks under 30 gallons

Examples: Lee’s Undergravel Filter, Aquarium Technologies Undergravel Filter.

4. Sponge Filters

Sponge filters are simple, porous foam pieces attached to an air pump. Airflow draws water through the sponge, trapping particulates. Sponges host beneficial bacteria.

Pros:

• Very inexpensive
• Simple setup and maintenance
• Gentle water flow for fry/bettas
• Supplements oxygenation

Cons:

• Lower flow rates than powered options
• Can clog faster than other media types
• Require air pump and tubing
• Some noise from air bubbles

Good for:

• Fry and breeding tanks
• Hospital/quarantine tanks
• Aquariums under 20 gallons
• Low-tech planted tanks
• Betta tanks

Examples: Marina Slim S10, Aquarium Co-Op Ultra Fine, Hydro-Sponge Pro

5. Internal Power Filters

Internal power filters are submersible units with filter media that are mounted inside the tank. Impellers push water through the filter cartridge.

Pros:

• Compact and space-saving
• Simple setup
• Adjustable flow control
• Customize filter media

Cons:

• Limited filtration capacity
• Water currents are less controlled
• Cartridges can clog quickly
• Visible equipment in the tank

Good for:

• Nano and desktop aquariums
• Tanks under 20 gallons
• Bettas and shrimp
• Hospital/quarantine systems

Examples: Zoo Med Nano 10, Marineland Duetto, AquaClear Quick Filter.

Best Freshwater Aquarium Filters for Beginners

Based on the above criteria, here are our top picks across different filter types and budget ranges:

Under $50

• Hang-on-back: AquaClear 20
• Sponge: Hydro Sponge Filter Pro
• Internal: Zoo Med Nano 10

$50 to $100

• Hang-on-back: AquaClear 50
• Canister: Fluval 107

$100 – $150

• Canister: Fluval 207
• Hang-on-back: Marineland Magnaflow 360

Over $200

• Canister: Fluval FX4
• Canister: Eheim Classic 600

Wrapping Up

Choosing the right aquarium filter doesn’t need to be complicated, especially for beginners. Focus on getting a filter properly sized for your tank’s capacity and stocking level. 

HOB and canister filters offer the best all-around performance, but there are budget-friendly options like sponge filters for smaller setups. 

Set up your filter properly and keep up with maintenance, and your tank inhabitants will enjoy clean, healthy water for years to come!