The Ultimate Guide To Keeping Tropical Fish

How to set up a tropical fish tank

Setting up your aquarium may seem a little daunting, but with the right approach, it's straightforward and fun! This section covers everything you'll need to know to establish a healthy aquarium.

1: Choosing your aquarium

Rectangular tanks are perfect for beginners. These tanks are easier to clean, provide ample swimming space, and allow for better gas exchange. A 60cm tank (around 54L) is perfect for a small community of fish, but large tanks (180L+) allow for more variety of species, and more stable water conditions.

When choosing your tank, consider the following:

• Fish species and size (as adults)
• Available space in your home
• If you'd like a heavily planted tank

Browse our range of tropical aquariums to find the perfect one for your home.

2: Aquarium placement and cabinets

Aquarium placement:

Choosing the right location is essential for both safety and enjoyment. Avoid situating your tank in direct sunlight, near a radiator, or in a high-traffic area. When filled with water, aquariums are very heavy, so they should be situated on a purpose-built cabinet capable of supporting the weight. Be sure that the surface is level and that access is easy for maintenance.

Choosing the right room:

In most houses living rooms offer the best view of your aquarium, but kitchens can work and even bedrooms with quiet equipment. Avoid areas with sprays, perfumes, or frequent temperature fluctuations. Conservatories tend to have too much sunlight, which leads to algae growth and temperature fluctuations.

Safety and stability

• Keep your aquarium near a power outlet with sufficient plug space
• Avoid overloading outlets
• Drip loops on cables prevent water entering the socket
• Ensure the floor can bear the weight of your tank
• Place aquariums only on a level surface
• Situate larger tanks on concrete or sturdy wooden floors
• Avoid high-traffic areas and vibrations from appliances or speakers

3: Heating and lighting

Tropical fish require water around 24°C. A heater rated at 1 watt per litre is ideal, so a 100L aquarium would need a 100W heater. Complement the heater with a thermometer to monitor the temperature of your water, keeping it safe for aquatic life.

Proper lighting supports fish health and live plant growth. Built-in LEDs work well for most tanks, but plant-specific lighting is ideal for heavily planted setups. Lights should be turned on for a maximum of 8-10 hours each day to reduce the growth of algae.

Have a look at our range of fish tank lighting and find the perfect system to complement your aquarium.

4: Filtration and aeration

Filters are an essential for maintaining water clarity and a healthy tank. Internal filters are simple, perfect for small tanks, whereas external units are better for large tanks, or tanks with a high waste load. 

Air pumps are optional, but they increase oxygen levels aid water circulation. When connected to an airstone, you can create a bubble wall that adds interest for you and your fish. Air pumps are also ideal to be used as a backup in the event your filter fails.

Internal vs external filter

Ideally, internal filters are best in smaller tanks, and external in large tanks, but which is right for you?

Filter Type	Pros	Cons
Internal Filter	- Easy to install and maintain - Affordable - Great for beginners - Compact	- Takes up swimming space inside tank - Limited filtration power - Needs more frequent cleaning
External Filter	- More powerful - Saves space inside the tank - Handles large bioloads - Less frequent cleaning	- Higher cost price - More complex setup - Can look a little bulky if not stored in a cabinet

5: Choosing gravel and sand substrates

Substrates affect the health of your plants and fish. Inert substrates are ideal for use with freshwater aquariums. Fine sands are better suited for bottom-dwelling fish, while medium or coarse gravel is easier to keep clean with a gravel vacuum, so keep an eye on grain size when choosing.

Natural coloured substrate helps fish feel more secure, but darker colours enhance the vibrant colours of your fish. You may even choose a vibrant colour, or a neutral one to complement your decorating however you like. The depth should be around 5cm, sloping from back to front for debris collection and perspective. For planted tanks, you'll need a nutrient rich aquatic soil.

Tip: Rinse substrate before use to remove dust particles.

Explore our aquarium substrates, all in a range of colours and grain sizes.

6: Decorating your aquarium

Decorating your aquarium isn't just about aesthetics, it's essential for a thriving tank. Creating hiding places reduces stress, keeping your fish healthier. Decorations also create surface area that allows beneficial bacteria colonies to establish.

Rocks, pebbles, wood, and plants are a staple for a natural aquarium. However, you may prefer to use artificial plants and resin decorations for easy maintenance. 

Check out our extensive range of aquarium decorations to style your tank today.

7: Filling and treating your tank

Make sure to use a dechlorinator with any tap water that is added to your aquarium to protect your fish. This applies for any water added in the future too. You may consider using bottled bacteria to establish biological filtration in advance, which speeds up the cycling process. Run your filter and heater for at least 24 hours before adding aquatic creatures, and monitor the water parameters with water tests to ensure the conditions are suitable for your chosen species.

8: Adding fish and feeding

Fish should be introduced gradually, starting with hardier species that are suitable for your tank. Feed your fish with only what can be consumed within a few minutes. This prevents excess waste that degrades your water quality. Providing a variety of food types including dry, frozen, or live foods supports health and boosts colouration.

Tip: Add a few fish at first, gradually adding more when the ecosystem is more stabilised.

Shop our selection of tropical livestock to find the best species for your setup.

What do I need to set up a tropical fish tank?

To get started you'll need:

• Aquarium and cabinet
• Heater and thermometer
• Filter (internal or external)
• Lighting (or plant specific lights for planted tanks)
• Substrate (gravel, sand, or planting soil)
• Water conditioner
• Test kit
• Aquarium decorations
• Fish food
• Net and cleaning tools

Frequently asked questions

What other creatures can I keep with fish?

A lot of non-fish species aren't suitable to keep with a community of fish, including frogs, turtles, and some species of snails and shrimp. 

• Snails: Nerite and Ramshorn snails are perfect for community tanks, and even keep your tank clean!
• Shrimp: Freshwater shrimp such as Cherry or Amano are great for planted tanks, however they may be eaten by large fish.
• Frogs: African dwarf frogs can cohabit with small fish.
• Turtles and crayfish: Unsuitable for cohabiting with fish

Tip: Predatory and invasive species should be avoided. If in doubt, stick with peaceful fish.

How long should I leave my tank before adding fish?

A new aquarium needs time to mature. Beneficial bacteria needs to establish to convert toxic ammonia into less harmful compounds. You can cycle a tank without fish using fishless cycling methods, such as bottled beneficial bacteria and ammonia, or add hardy fish carefully under controlled conditions.

Be sure to monitor ammonia, nitrite, and nitrate levels with aquarium test kits. Once ammonia and nitrite are consistently zero, the tank is ready for stocking. This process takes around 2-6 weeks, depending on your chosen method.

Tip: Never add livestock to a new tank without testing the water first.

Our range of aquarium test kits help to ensure safe water quality, shop today.

How often should I change the water?

Changing water is essential for removing nitrate and phosphates, keeping your aquarium healthy. A good routine to follow is conducting a 25% water change every two weeks. The frequency may need to be adapted based on your nitrate levels and fish load. Always match the water temperature to avoid the drastic fluctuation affecting your fish, and use dechlorinator when adding any tap water.

You can easily change the water using a jug, tap water, and dechlorinator, but there's plenty of equipment available that will make this process less time consuming and laborious. We recommend:

• Gravel vacuum
• Algae scraper
• Water siphon
• Aquascaping scissors (for plants)
• Fish net
• Glass cleaner
• Aquarium tweezers

Have a look at our aquarium cleaning equipment to stock up on everything you'll need.

Tip: Changing a little water frequently is better than infrequent, large changes.

Common tropical tank mistakes

New fishkeepers often make errors, typically the following:

• Choosing a tank that's too small - smaller tanks are harder to maintain due to water fluctuations. We recommend to choose the largest tank your budget and space allow.
• Adding fish immediately - introducing fish before the water has stabilised can expose them to harmful elements such as ammonia or nitrite.
• Overfeeding fish - overfeeding pollutes the water and even stresses fish, only feed what can be consumed within a few minutes.
• Not testing water - skipping water tests means that water parameter issues can go undetected.
• Skipping water changes - can cause poor fish health.

Patience really pays off in the aquarium hobby. Allow your tank to stabilise before stocking gradually, and make sure to keep on top of water changes.

Ready to set up your tropical aquarium?

With careful planning and following each step carefully and one-by-one, you'll be sure to have your fish tank set up and full of life in no time.

Your aquarium is more than just a tank, it's a thriving ecosystem. Start yours today with our full aquarium range of tanks, equipment, treatments, and fish food.