Aquarium Equipment Checklist: What You Need for Different Tank Sizes

Setting up an aquarium is more than simply choosing a tank and adding fish. The right equipment helps maintain clean water, stable temperature, proper oxygen levels, and a healthy environment for fish and aquatic plants. But the equipment you need can vary depending on your aquarium size, fish species, stocking level, and whether you are keeping a planted or non-planted aquarium.

This aquarium equipment checklist explains the essential equipment required for different aquarium sizes, from small beginner tanks to large community and planted aquariums.

Whether you are setting up your first aquarium or upgrading an existing setup, this guide can help you understand what equipment you actually need.

Why Is Aquarium Equipment Important?

An aquarium is a small artificial ecosystem. Fish continuously produce waste, uneaten food can break down, and beneficial bacteria need a suitable environment to process harmful substances.

Proper aquarium equipment helps manage these conditions.

A good setup can provide:

• Mechanical and biological filtration

• Adequate water circulation

• Oxygen exchange

• Stable water temperature

• Appropriate lighting

• A suitable environment for aquatic plants

• Easier aquarium maintenance

The equipment required depends largely on the tank's size and inhabitants.

Basic Aquarium Equipment Checklist

Before looking at different tank sizes, here are the main equipment categories to consider:

1. Aquarium Filter

A filter is one of the most important pieces of aquarium equipment. It helps remove suspended particles and provides space for beneficial bacteria.

Depending on your aquarium, you can choose from:

• Internal filters

• Hang-on-back filters

• Sponge filters

• Canister filters

• Undergravel filters

When selecting a filter, consider the aquarium's water volume, fish load, and required flow rate.

For heavily stocked aquariums, a stronger filtration system may be required than the minimum recommended for the tank volume.

2. Aquarium Light

Lighting is important for visibility and becomes especially important when keeping aquatic plants.

For a basic fish-only aquarium, a simple LED aquarium light may be sufficient.

For planted aquariums, choose lighting according to the plants you intend to grow. Low-light plants generally have different requirements from demanding carpeting or high-light plants.

3. Aquarium Heater

Tropical fish generally require stable warm water. An aquarium heater helps maintain a consistent temperature instead of allowing the water temperature to fluctuate with room conditions.

Choose a heater according to:

• Aquarium volume

• Room temperature

• Required water temperature

• Heater wattage

A thermometer is also useful for checking whether the heater is maintaining the desired temperature.

4. Air Pump and Air Stone

An air pump can improve surface agitation and gas exchange.

An air stone connected to an air pump produces bubbles that increase water movement at the surface.

An air pump can be particularly useful when:

• The aquarium has high fish stocking

• Surface agitation is low

• Additional aeration is required

• A sponge filter is being used

Remember that bubbles themselves are not the main source of oxygen. Surface movement and gas exchange are important.

5. Aquarium Substrate

Substrate provides a base for the aquarium and can contribute to its appearance and functionality.

Common choices include:

• Aquarium gravel

• Sand

• Aquasoil

• Decorative substrate

• Specialized planted-tank soil

For planted aquariums, nutrient-rich aquasoil may be preferred, while gravel or sand can work well for many fish-only setups.

6. Water Conditioner

Tap water can contain chlorine or chloramine, which can be harmful to fish and beneficial bacteria.

A suitable aquarium water conditioner should be used when preparing tap water for the aquarium.

7. Aquarium Maintenance Tools

A few simple tools can make regular maintenance much easier:

• Aquarium siphon

• Gravel cleaner

• Algae scraper

• Aquarium net

• Water-change bucket

• Glass cleaner or magnetic algae cleaner

These aren't always part of the aquarium's visible equipment, but they are extremely useful for keeping the tank clean.

Aquarium Equipment Checklist for Different Tank Sizes

There is no single equipment setup that works for every aquarium. Below is a practical starting point.

Small Aquariums: Up to 20 Litres

Small aquariums can look simple, but they require careful maintenance because water parameters can change quickly in a smaller volume.

Basic checklist:

☑ Aquarium tank
☑ Suitable filter
☑ LED light
☑ Thermometer
☑ Water conditioner
☑ Aquarium substrate
☑ Aquarium net
☑ Siphon for water changes

A heater may be required if you are keeping tropical fish and the room temperature is not stable.

Avoid overstocking small aquariums. The available swimming space and water volume should always match the livestock.

20–60 Litre Aquariums

This range is popular among beginners because it provides more flexibility than very small tanks.

Recommended equipment checklist:

☑ Aquarium tank
☑ Internal, sponge, or hang-on-back filter
☑ Aquarium LED light
☑ Heater for tropical fish
☑ Thermometer
☑ Substrate
☑ Water conditioner
☑ Aquarium net
☑ Siphon/gravel cleaner
☑ Air pump and air stone, if required

This size range can work well for small community fish, shrimp, or selected planted aquarium setups, depending on the tank dimensions and livestock.

60–120 Litre Aquariums

As aquarium volume increases, you have more options for fish, plants, aquascaping and filtration.

Aquarium equipment checklist:

☑ Aquarium tank
☑ Internal, HOB, or canister filter
☑ Appropriate aquarium light
☑ Aquarium heater
☑ Thermometer
☑ Substrate
☑ Water conditioner
☑ Air pump, if required
☑ Aquarium maintenance tools
☑ Timer for lighting

A canister filter can be particularly useful when you want higher filtration capacity while keeping equipment outside the aquarium.

For planted aquariums, lighting should be selected based on plant requirements rather than simply tank size.

120–250 Litre Aquariums

Larger aquariums generally require more capable filtration and equipment.

Recommended checklist:

☑ Large aquarium
☑ High-capacity filter
☑ Canister filter or suitable external filtration
☑ Aquarium heater
☑ Aquarium thermometer
☑ Appropriate LED lighting
☑ Substrate
☑ Water conditioner
☑ Air pump and air stone, if required
☑ Lighting timer
☑ Gravel cleaner
☑ Algae-cleaning tools

For a heavily stocked aquarium, filtration capacity should be selected according to both water volume and fish waste production.

If you are keeping a planted aquarium, you may also need additional equipment such as a CO₂ system depending on the plant selection.

Aquariums Above 250 Litres

Large aquariums require more planning because the equipment must handle a larger volume of water and potentially a larger biological load.

Large aquarium checklist:

☑ High-capacity filtration system
☑ Suitable aquarium pump
☑ Appropriate aquarium heater or multiple heaters
☑ Thermometer
☑ High-quality aquarium lighting
☑ Substrate
☑ Water conditioner
☑ Aeration system, if required
☑ Lighting timer
☑ Maintenance equipment
☑ Backup equipment where appropriate

For very large aquariums, external canister filters, sump filtration, or other advanced filtration systems may be considered depending on the aquarium design.

Aquarium Equipment Checklist for Planted Tanks

A planted aquarium has additional requirements compared with a basic fish-only setup.

Essential planted aquarium equipment

☑ Aquarium filter
☑ Suitable planted-tank LED light
☑ Aquarium substrate or aquasoil
☑ Thermometer
☑ Water conditioner
☑ Maintenance tools

Optional equipment

Depending on the plants:

• CO₂ system

• CO₂ diffuser

• Bubble counter

• Fertilizer

• Aquarium plant tools

• Lighting timer

• Surface skimmer

Not every planted aquarium needs CO₂. Low-tech planted aquariums can be successfully maintained with suitable plants, lighting and basic care.

Aquarium Equipment Checklist for a Fish-Only Tank

A fish-only aquarium can have a simpler setup.

Basic checklist:

☑ Aquarium tank
☑ Filter
☑ Aquarium light
☑ Heater for tropical fish
☑ Thermometer
☑ Substrate or bare-bottom setup
☑ Water conditioner
☑ Aquarium net
☑ Siphon
☑ Maintenance tools

The most important consideration is matching filtration and aquarium size to the fish being kept.

How to Choose the Right Aquarium Filter

One of the most common questions from new aquarium owners is: “What size filter do I need?”

Instead of looking only at the aquarium's litre capacity, consider three factors:

Aquarium volume

First calculate the approximate water volume of the aquarium.

For example:

Length × Width × Height = Volume

If measurements are in centimetres:

L × W × H ÷ 1000 = approximate litres

Remember that actual water volume will be lower after accounting for substrate, decorations and other equipment.

Fish stocking

A lightly stocked aquarium and a heavily stocked aquarium of the same size may require different filtration.

More fish generally means:

More waste → higher biological load → greater filtration requirements

Filter flow rate

Look at the manufacturer's stated flow rate in LPH (litres per hour).

However, the advertised flow rate may be measured under conditions different from your actual aquarium setup. Flow can be reduced by filter media, tubing, bends and head height.

Therefore, don't choose a filter based on LPH alone.

Do You Need an Air Pump in Every Aquarium?

No.

An air pump is not automatically required for every aquarium.

If your filter creates adequate surface movement and gas exchange, additional aeration may not be necessary.

However, an air pump can be useful for:

• Sponge filters

• Breeding tanks

• Quarantine tanks

• Heavily stocked aquariums

• Additional surface agitation

• Situations where extra aeration is desirable

The actual requirement depends on the aquarium's design and livestock.

Do You Need a Heater?

That depends on the fish species and room temperature.

Tropical fish generally need stable warm water, making a heater important in many setups.

Coldwater species may have different temperature requirements.

Instead of choosing a heater only by tank size, consider:

• Aquarium volume

• Desired temperature

• Ambient room temperature

• Seasonal temperature changes

A thermometer should be used to verify the actual water temperature.

Do You Need a UV Sterilizer?

A UV sterilizer is not essential for every aquarium.

UV equipment can be considered for specific situations where controlling suspended microorganisms or green-water organisms is desired.

It should not replace proper mechanical and biological filtration.

For most beginner aquariums, priority should be given to:

Correct filtration + proper stocking + regular maintenance + stable water parameters.

Common Aquarium Equipment Mistakes to Avoid

Choosing a filter only by tank size

Two aquariums with the same water volume can have very different filtration requirements depending on their fish load.

Using excessive lighting

More light does not automatically mean a healthier planted aquarium. Excessive light can contribute to algae problems when other factors are not balanced.

Overcrowding the aquarium

Adding too many fish increases waste production and biological demand.

Skipping water conditioning

Untreated tap water can harm fish and beneficial bacteria.

Buying equipment without considering maintenance

A filtration system should not only be powerful; it should also be practical to clean and maintain.

Quick Aquarium Equipment Checklist

*Heater requirements depend on fish species and room temperature.

Final Thoughts

The right aquarium equipment depends on much more than tank size. Fish species, stocking level, planted or non-planted setup, room temperature and maintenance routine all influence your equipment choices.

For beginners, start with the essentials: a suitable filter, appropriate lighting, temperature control when required, water conditioner, substrate and basic maintenance tools.

As your aquarium becomes more advanced, you can add equipment such as canister filtration, CO₂ systems, specialized lighting, surface skimmers and other accessories according to your needs.

Before buying equipment, calculate your aquarium volume and consider the fish and plants you plan to keep. Choosing equipment based on the complete setup can help you create a healthier and easier-to-maintain aquarium.

Looking for aquarium filters, pumps, lights, substrate, fish food or planted aquarium equipment? Explore Greenfin The Pond Studio's aquarium collection and choose equipment suited to your setup.