Decorating a fish tank isn’t as hard as you thought. Before your fish can come into the picture, you need to create a suitable home for them. In this article, we’ll explain how to incorporate plants, rocks/stones, substrate, and other decoratins into your fish tank.

How to decorate a fish tank

The importance of substrate

When you begin decorating, start from the bottom, working your way upwards. The starting point and the very base of your aquarium should be the substrate.

Aquarium substrate

Substrate comes in various kinds, depending on shape, size, color and purpose. It’s up to you to pick the one best suitable for your tank. A general rule of thumb is to cover at least 2 to 2.5 inches of your aquarium with substrate. You can use an online aquarium substrate calculator to determine how many lbs of substrate you’ll need.

Step 1: Selecting substrate for your fish tank

Substrate serves various purposes, so you must choose it based on the fish and plants you plan on getting.

There’s a certain amount of bacteria in every aquarium, both beneficial and harmful. Beneficial bacteria are in charge of biological filtration. They’ll usually colonize the filter, but they also dwell in substrate, where they multiply. If they don’t have a shelter, they’ll grow in other places and it’s not guaranteed that they’ll do their job as well. Just like with bacteria, substrate provides shelter for your fish and they can also lay eggs in it.

Aquarium substrate: a few useful tips

Substrate as shelter
Certain fish use gravel to lay their eggs. In that case, use a larger (bigger-grained) substrate. It captures the eggs and keeps them out of reach.

Sand or gravel?
Sand, as a substrate, is beautiful – but very dense. Plants can’t grow roots in sand – you should only use it if you don’t plan on keeping any rooted plants. Some plants, like the Anubias Nana, absorb nutrients directly from the water – and don’t need to be planted to grow. 

Substrate type
If you want to increase the pH balance of your water, buy crushed coral, coral sand, crushed marble, crushed limestone or aragonite. They contain a high concentration of calcium carbonate. Peat is an ideal source of nutrients for certain species of freshwater plants and can also provide shelter for Corydoras catfish.

Substrate size
Gravel comes in various sizes, from 0.5 mm and above. To ensure that your plants can easily grow roots, you should always buy gravel that’s at least 1 – 2 mm wide.

Substrate color
Darker-colored substrate is the best option for colorful fish, because it will make them much more noticeable. It also makes waste, dirt and debris much less noticeable, and generally requires less maintenance. White substrate has a more natural look, it gets dirty fast and requires constant cleaning.

Step 2: Plant selection

Plants are always a perfect addition to your tank because they add color to the ambient and serve as an additional shelter for your fish. They’re also a great natural source of oxygen and will help prevent algae growth by consuming light and various nutrients that cause algae to thrive.

How to decorate an aquarium with plants

Plants are so popular in aquascaping that many owners dedicate their aquariums entirely to them. Plants are suitable for almost every fish tank, seeing as they’re natural, useful and offer other benefits. They’re in charge of oxygen production and harbor helpful bacteria that help filtrate water. They can also serve as food for your fish. You must understand your species of fish before adding plants to your tank. For example, certain types of fish are greedy herbivores. Cichlids are very aggressive and will wipe your aquarium out of plants. Avoid planting them in a tank with this species of fish.

In order to grow demanding plants, your tank mustn’t be too deep, because light won’t be able to reach them.

Different plants grow at different rates, and you should always consider this when placing them into your tank. Short plants should be used as the foreground. Medium plants go in the middle and tall plants in the back. You can’t place a tall plant in the front of your fish tank, as it’ll block the view.

Tip: Before buying a certain plant, make sure to ask around and determine how much it’ll grow, because certain plants can be small when you buy them and then reach a much larger size.

Plant selection: Plant difficulty

How to decorate a fish tank with plants
A lush Amazon style aquarium

While some plant species will require no additional care and equipment, some types can get rather expensive to keep. Difficult plants will require lots of light, a CO2 supply and fertilizer to grow. In accordance with their needs, we can group aquarium plants into 3 types:

Difficult – these types of plants need specific conditions to thrive in. They need a lot of light and CO2. A perfect example is the Hemianthus callitrichoides, also known as the “Cuba” plant. It’s one of the smallest aquarium plants in the world. It’ll only grow at the bottom of your tank, covering each nook and cranny like a carpet.

Easy –  these plants can grow almost anywhere, even in the harshest conditions. They don’t need much light at all, and are a great choice if you want a cheap setup. For example, the Anubias barteri plant, which is a small and leafy plant originating from Cameroon.

Medium  – these types of plants only need a small dose of CO2 and medium lighting in order to grow. They aren’t as needy as their aforementioned counterparts. For example, the Marsilea crenata. It’s a small type of fern that originates from Asia. It can tolerate the hottest temperatures and lack of light.

You have loads of plant options to choose from, such as moss, grass, marsilea minuta, etc. It all depends on your personal preferences and whether your plant of choice will be suitable for your fish.

Plant selection: Artificial plants

Artificial plants are easier to tend to, seeing as they can’t grow, die and don’t require specific needs. However, they can bring about certain complications regarding the composition of your water. They don’t absorb toxins like living plants do, can’t produce oxygen and are inedible to aquarium inhabitants. Poorly made artificial plants can produce harmful elements which might eventually contaminate the water. 

Step 3: Adding other decor elements to your fish tank

Other decorations: Aquarium rocks

Aquarium Rocks
Aquarium decorated with Dragonstone rocks

Aquarium rocks can give a more natural feel, plus they’re aesthetically pleasing and provide shelter for you fish. You usually place the rocks first, then cover the bottom substrate. Before adding the rocks, ensure that you have made them safe by cleaning them. Make sure they aren’t home to other animals, and aren’t sharp, because this can injure your fish.

Stones and rocks are heavily used in aquascaping. This refers to the art of arranging plants, rocks, driftwood etc. within an aquarium in an aesthetically pleasing way. There are multiple aquascaping styles in the world, with the Japanese style being the most popular. The two subtypes within the Japanese style are the Nature style and the Iwagumi style.

The Nature style

Takashi Amano introduced this style to the world in 1990. His concept lies in selecting only a couple of plant species in combination with carefully selected stones, rocks and driftwood. All in all, the whole philosophy is to use minimal decor. This stems from the Japanese concept which states that less is more. This style also limits the use of multiple colors. The most commonly used plants are Java moss, ferns, Riccia fuitans and other plants with small leaves.

The Iwagumi style

The main focus in the Iwagumi style is on stone selection. The Japanese believe that each stone plays a different role and has its own name. The concept of this style lies in selecting 3 main stones. One is larger and the remaining two are smaller. In other cases, you can also use additional stones. You should place the main stone in the center. Place the accompanying stones around it in peripheral positions. The focal point of the whole display is determined by the placement of the main stone.

The most popular aquascaping rocks and stones

The 3 most popular stones used in aquascaping are the Seiryu stone, Dragon stone and Lava rock.

The Seiryu stone is very famous for its looks, as it looks like a small mountain rock. Its look is very specific – sharp, uneven edges and crevices. It’s great for Iwagumi aquariums. Originating from limestone, it releases carbonates and can alter the composition of water. We recommend using it in smaller quantities.

When we say “Dragon stone”, the first thing that comes to mind is Game of Thrones. But we don’t mean the famous castle with the same name as the actual stone. Its specific characteristic are its jagged edges and multiple holes. It doesn’t release carbonates, so it doesn’t affect the chemistry of water. Therefore, you can use it in large quantities. Its holes can collect mud, dirt and soil. If you don’t wash it properly, it can get dirty fast.

Just like the name states, lava rock is of volcanic origin. It’s very light and spongy. Unlike the dragon and Seiryu stone, it doesn’t have large surface holes. However, it has millions of micro-holes that help with the formation of bacteria, such as Nitrobacter and Nitrosomonas. These bacteria are very important for the Nitrogen cycle of an aquarium. It doesn’t interfere with the chemistry of water. It’s also a very good substrate, as it can aid with oxygenation.

Other decorations: Driftwood

Aquarium driftwood

Driftwood is a very popular aquarium decoration. If you want your tank to look as natural as possible, driftwood is an absolute must-have. Before adding driftwood to your tank, you need to clean it thoroughly.

Other decorations: Aquarium backgrounds

An aquarium background is a great way to add more depth and a more realistic touch to your tank. When chosen properly, a background can serve as the centerpiece of your aquarium, and may be the only decoration you’ll ever need. On the other hand, if you don’t choose the adequate one for your tank, it can look very tacky. Aquarium backgrounds are usually either printed pictures that depict natural scenes, elements or actual 3D backgrounds that can help add more depth to your aquarium.

 Other decorations: aquarium ornaments

Aquarium ornaments are often disregarded as tacky – but with proper planning, they can bring your aquarium to life. Usually made from plastic, aquarium ornaments are often non-toxic, inedible and don’t pose a threat to fish. There are many aquarium decorations on the market and dozens of themes to choose from. The best part of decorating your aquarium using ornaments solely lies in your taste and creative abilities.

Step 4: How to maintain and clean your decorations

Maintenance: How to clean plants

In order for your fish tank to be both beautiful and functional, you have to clean every element of its interior thoroughly. If you want to get rid of algae, calcium deposits, tiny snails, etc. follow our tips to ensure that you have a happy and fresh environment for your fish!

Tip: Over time, algae build up will form on your plants, both living and artificial. You can get rid of algae by simply wiping down your plants with an algae pad or even a toothbrush. Rinse them off with cold water before putting them back into the water.

Tip: Lemon juice and salt can also eliminate algae. Mix 3 teaspoons of lemon juice with 1 teaspoon of non-iodized salt and rub the paste onto your plant. Gently scrub it down with a toothbrush. Before returning it back into the water, rinse the plant off well.

Tip: If you want to get rid of excess calcium build up on your plants, use vinegar. Soak your plant in half a cup of white vinegar and 1.89 l of water for 5 minutes. Rinse well before putting it back in the aquarium.

Tip: Snails can infest even the cleanest of aquariums, but thankfully, this tip will eliminate them. Soak your plant in 3.7 l of water and add half a tablespoon of potassium permanganate for 15 minutes. Rinse well before putting it back into the aquarium.

Maintenance: How to clean stones and driftwood

Before choosing driftwood for your tank, you’ll need to clean it by boiling it. If you don’t it will emit tannins, which can lead to water discoloration. Boiling the driftwood will prevent this from happening. Boil it for 1-2 hours and repeat the process once more.

Aquarium rocks and stones are much simpler to clean. Never boil aquarium stones to disinfect them, as some rocks can be hollow. The trapped air can expand from the heat, which could cause the rock to violently explode. Use a cleaning tool to scrub off any algae or other sort of build up. Soak them in salt water for 2-3 days after that.

Maintenance: How to clean gravel

Substrate (gravel) is very easy to clean. All you have to do is rinse it using water. The amount of gravel you should be able to fill your aquarium should be 2 to 3 inches deep. Usually, you’ll want to use one pound of gravel per each gallon of water.

You’ll need a bucket and sieve for the cleaning process. Place the sieve over the bucket and pour the gravel into it. Gently shake the sieve to filter it out. Pour water over it gently. You’ll have to do this multiple times until the running water turns clear.