How To Pick Supplies For Your 40 Gallon Aquarium

We here at Freshwater Central always suggest beginners start out with something between 20 and 40 gallon aquariums, and a 40 gallon tank is even a popular choice among experienced fishkeepers. These tank sizes offer enough space to explore your creative vision and house a variety of different species.

Forty gallons is a wonderful place to start as it requires less maintenance (with the proper equipment) than smaller tanks but offers a world of options for beginners and experts alike. There are plenty of options to choose from, and this article will be your guide to setting up a beautiful and functional 40 gallon tank.

40 Gallon Tank Versatility

The 40 gallon tank size is one of the most popular setups in the freshwater aquarium trade. The measure allows for a variety of decor and small to medium-sized aquarium inhabitants. They come in various shapes to fit every space in your home, which makes them very versatile.

You can choose from the standard rectangular shape, an angled set up to work in corners, circular fronted tanks that are great for viewing, or a specialty tank set up for breeding. Breeding tanks, often referred to as a 40 gallon breeder, are by no means solely meant for breeding. If you like the shape, it works just fine in a regular community tank.

Irregularly shaped tanks are great for viewing. However, they can pose a higher level of cleaning difficulty and leaks. For this reason, we recommend that beginners chose the standard, rectangular shape. It is easier to maintain a clean and healthy tank with this shape if you have little fishkeeping experience.

With the added space afforded by the 40 gallon size, you will have many options for stocking and a forgiving environment for experimenting with water parameters.

What You Will Need


No matter what size or shape of tank you choose, the simple fact is that aquarium environments are fragile. You will need specific equipment to ensure the health and happiness of your new pets. There are many things you’ll need to guarantee this health and safety, and it all starts with the tank and mechanical equipment.

Tank Material

The two most common choices for aquarium material are glass and acrylic. They both have their benefits and drawbacks. The benefits of acrylic are that it is lightweight and easy to move. This is particularly helpful if you’re placing or moving the tank on your own. Aquariums, when filled with decorations, water, and fish, are very heavy.

You should allow for a little over 8 pounds per gallon of water in your tank, so at the very minimum, a 40 gallon aquarium will weigh approximately 320 pounds – and that doesn’t even take into consideration the weight of substrate, decorations, and animals! However, acrylic tanks are more prone to unsightly scratches. Glass tanks are heavier but easier to clean and less likely to show ugly scratch scars.

On the other hand, acrylic tanks are less expensive, so you must weigh the cost of potential replacement against the unsightliness of scratches.


No matter which material type you choose, a quality tank stand is essential. While you can use a counter or tabletop as a holding surface for smaller aquariums, something as large as a 40 gallon tank will need a dedicated stand to ensure safety. Stands are usually constructed of metal or wood and contain a number of support points to supply good leveling to the bottom of the tank.

You can take any number of creative measures to decorate an aquarium stand to your taste and fit your decore. Or you can take a minimalist approach to minimize the look of the stand and make the aquarium the center of attention. Stands can also be used as storage for all your aquarium related supplies.



Even in homes with high lighting, you should have a devoted light source for your aquarium. We always recommend live plants for your aquarium, but even if nothing but your fish are living in your tank, lights should still be present. Aquarium inhabitants are living things, just like their owners, so having set times for high, low, and no light is vital to establishing a daily routine.

Some freshwater fish are even more active with different light levels, so being able to control it is an essential factor in creating a healthy environment for your pets. Built-in LED lights in premade aquariums are usually suitable when adjusted to the time of day. Still, you can also install more lighting or remove excess brightness as you gain more experience.


Every, I repeat, every aquarium needs a filtration system! The type you choose is a personal one, but as long as you maintain vigilance to ensure it is working correctly, you won’t go wrong. One of the most common filter options is one that hangs over the back (HOB) of your tank. With this option, you can hide most of the mechanics behind plants and decorations.

Suppose you are positively opposed to HOB filters, which includes the entirety of the filtration system. In that case, you can pick a design that lies under your substrate or something that relies on an air pump to move the water and a separate filter to catch aquarium debris.


Even if you live in a climate that is considered appropriate for freshwater fish, you should still have a heater. I know it can seem counterproductive at first glance, but having a heater ensures that your aquarium temperature remains constant. Temperature fluctuations can be very harmful to your aquarium pets’ health, so having a dedicated heater will help control fluctuations.

Cleaning Supplies


Two things you should have as absolute essentials for cleaning supplies in your arsenal are a gravel siphon and a good, clean sponge. Cleaning is essential to your fish’s health, so regular gravel sweeping is necessary to keep the substrate clean. Other essentials are soft sponges.

Unused sponges, or those dedicated to aquarium use, will be less likely to cause scratches or harm to freshwater pet tanks. You should never use any sort of chemical cleaners in your tank, even when it’s empty. Even trace amounts of cleaning agents left over after you clean and rinse an empty tank can cause your fish’s illness or death.


Substrate is the material that layers the bottom of your tank. Various materials can be used as substrate, such as aquarium gravel, sand, and small pebbles. Which you should choose depends on what animals you plan to keep and your own personal style. If your fish have delicate scales, fins, or don’t have scales at all, you should stick to fine-grained sand.

Aquarium sand is soft and won’t hurt your fish. If that isn’t a concern for your chosen fin friends, gravel is a perfectly acceptable option. Small pebbles can be fine too, just make sure the pieces aren’t so large that fish poop and uneaten food can lodge in the cracks. This creates a breeding ground for harmful bacteria that may make your fish sick.

Plants and Decorations

Lastly, you will want to decide on any plants or decorations you want to include in your aquarium. This step is where you can really customize the look of your tank. Popular choices for decorations often are based on a central theme, such as a sunken pirate ship or an abandoned underwater castle. If the tank is for a child, let them pick their favorite movie or tv show to show off their interests! 

Decorations are usually made of plastic or ceramic, which can have sharp edges. Before adding them to your tank, run a tissue along all surfaces that your fish may come into contact with. If it can tear a tissue, then it can tear their fins. Smooth out any rough edges with a nail file or fine-grained sandpaper.

You can choose either live plants or plastic for your tank. Both have benefits and drawbacks. Plastic plants require less maintenance, but they can also have sharp edges that will need to be smoothed out. Live plants take a little more work, but they help to oxygenate aquarium water, remove water pollutants, and create a more natural environment for your fish.

Stocking Options


How to fill the shared space of a 40 gallon tank can seem daunting to a beginner, but there are many fish that are both delightful to watch and easy to keep for all aquarium owners. Deciding which pets to purchase is super fun; just make sure to research the different species to ensure they will all get along.

Additionally, make sure not to overstock your tank. You should have no more than one inch of fish for every gallon of aquarium water. If you’re looking for the most beautiful freshwater aquarium fish available, check out our guide for ideas!

Some standard 40 gallon stocking options are:

Danios: Danios come in a variety of patterns are very boisterous fish. They will continuously be swimming back and forth throughout the top and middle sections of the tank. Make sure not to keep them with overly shy species, as their active lifestyle can make less outgoing fish nervous.

Guppies and Endler’s Livebearers: These colorful tank additions are absolutely stunning and some of the most popular choices for tanks of 10 gallons or more. They get along with all other peaceful fish and create flashy displays.

Plattys and Mollys: These two species are very hardy and get along well together. They tolerate most normal water parameters, so they are easy to care for. 

Cory Cats: If you’re looking for a great addition to add movement and color to the bottom of your tank, corys make a great choice. They are a little on the timid side and feel safest in larger groups of their own kind, so make sure to keep a nice sized group to keep them happy.

Loaches: If Cory cats aren’t your cup of tea, you should consider loaches! They come in several body sizes and color patterns, so you are sure to find one that will suit your tank. Most loach varieties are very active, particularly at night, but they have sensitive scales (some have no scales at all!). To keep them from injury, use aquarium sand as your substrate. Khuli loaches are a popular choice due to their eel-like appearance. Also, make sure to choose tankmates for loaches with care. They are classified as semi-aggressive, and snails are one of their favorite foods.

Goldfish: Goldfish are one of the most common freshwater aquarium fish for a reason! They come in several colors and body options and are very peaceful to watch. Forty gallons is really the smallest tank size they should live in, as they can reach up to a foot long when fully grown!

Shrimp: Freshwater shrimps, such as red cherry, Amano, and bamboo shrimp make excellent pets that double as a cleanup crew. They are always on the move as they graze to find their food. They will help to keep your tank clean and are a blast to watch.

Snails: Snails are the perfect tankmate for all peaceful community tanks. They come in nearly every color imaginable and tons of different sizes and shapes. They are very soothing to watch as they glide about the tank and even help get rid of pesky algae.

Putting it all Together

Now that you have all the things you need for a 40 gallon setup, it’s time to put it all together and start enjoying your tank. We recommend reading our much more detailed 40 gallon aquarium setup guide, however, here’s a quick overview.

Follow these steps to get started:

  1. Purchase tank, stand, and equipment
  2. Find a suitable place in your home (away from windows and heating/cooling vents)
  3. Assemble the stand and place the aquarium on it
  4. Assemble hardware equipment (filter, pump, etc.), place it in the tank, but DO NOT turn it on yet.
  5. Add substrate and large decorations
  6. Fill tank halfway
  7. Add any live plants or small decorations
  8. Finish filling the tank
  9. Turn the equipment on and let the tank cycle
  10. Add fish a few at a time 


And there you have it! Your new 40 gallon aquarium is set up and ready to go. With proper maintenance, you will be enjoying this tank for many years and providing a safe and happy home for many new fin friends. We hope this article has been instructive and given you new ideas and passion for this rewarding hobby.

Have questions about setting up a 40 gallon aquarium? Any advice you’d like to share with others? Please leave them in the comments below!

Be the first to comment

Leave a Reply

Your email address will not be published.