How To Design a Biotope Aquarium or Paludarium

For a lot of species, we try to mimic or recreate the natural biotope of where the species live in the wild. This is also the same within the watery worlds of fish, amphibians and aquatic reptiles. But sometimes it is difficult to get the right esthetics to mimic this natural biotope. In this snippet, there are some tips and tricks on how to design a biotope aquarium or paludarium.

To find more information about what a biotope aquarium or paludarium is I like to refer to the website of ‘Bioptope Aquarium‘. Here you can find a very extensive description of what biotope aquariums are.

Research and make a plan

You start with research the natural habitat of the species planned to exhibit in the enclosure. Start with answering these questions:

  • Where do they live?
  • What are the climate parameters? How are the seasons?
  • What are the lightning hours? What is the UV-index? The lumen or lux of the light?
  • What are the water values? Is it slow or fast streaming?
  • What plants grow there?
  • What substrate is there in the river/lake?

You can use this example factsheet to collect all necessary information. With the answers to these questions, you can start designing the different aspects of the aquarium or paludarium. This will consist of three main parts: Technical design, hardscape design, softscape design.

Technical design

Naturally, the size of the enclosure is key to the species you want to exhibit in the aquarium or paludarium. Make sure the size fits the need of the species planned. When the size of the aquarium or paludarium is known you can think of the technical design of the enclosure. There are three key elements to consider within the technical design: Aquarium filter, heating/cooling and light. These three elements are also affected by each other.

Aquarium filter

The aquarium filter is (together with the substrate) important to keep your enclosure clean and bio-active. Within the filter are most of the bacteria. The mechanical elements and bacteria together remove and breakdown physical and soluble chemical waste products. So the aquarium filter capacity must be adjusted to the size of the water volume, species footprint and water flow desired in the aquarium or paludarium. An aquarium filter with larger capacity can create faster water flow, depending on how the outflow is made. You can also use a streaming pump or create a water stream/waterfall for faster water flow. For esthetic and handling reasons it is advisable to use an external aquarium filter.


For the heating of the aquarium, you can use an aquarium heater. But it is a better practice to have your heater within the aquarium filter (e.g. most types of Eheim filters) so that animals cannot get burned by it. Keep in mind that the ambient temperature also influences the water temperature. Ambient temperature will be higher if there is a lot of lightning above the aquarium or paludarium, especially if you not use LED lights. Floor heating can be used, but with aquariums with plants, it is not advisable. The roots of the plants will rot faster when aquariums are heated from below. It is easier to heat your aquarium than cooling it. So if you have planned a cold water aquarium be aware not to place it within a high ambient environment. You can cool an aquarium in two ways. With ventilation that blows air over the water surface, but it is not practical within a paludarium. Another way of cooling the water is by using a so-called ‘aquarium chiller’ (e.g. Teco TK500). This chiller will keep continuously the water at the same temperature. If the species live in a seasonal biotope, it is important to mimic (water)temperature changes as well.


For lightning, you can choose between a variety of lights. For aquariums LED lights are advisable, but also TL-lights are possible to create enough light. The benefit of using LED light is that most types can be dimmed or automated (sunrise-, sundown-effect). With paludariums in most cases, you need UV-light for the animals, and this is also beneficial for the plants. Be aware that TL-lights and UV-lights produce warmth. Also, use a light cycle that fits with the need of the species and adjust it when the animal lives in a seasonal biotope.

Hardscape design

The hardscape is all not living materials that are used to mimic the biotope and environment of the species. There are three main aspects of the hardscape: Background, rocks and substrate. In this stage, you will build the actual layout of the enclosure.


As background most often cork or fern root is used. This is especially useful in tropical biotopes. You can also use a background of stacked rocks when the biotope is a fast streaming river or a rocky lake. Another way is building a background by yourself of styrofoam and epoxy resin. You can shape it as you desire. You can find best practice on the internet, for example like this: DIY Background.

Rocks and stones

Rocks and stones can be used to make the aquarium more appealing. When mimicking a biotope it is necessary to use stones that match the colour and shape of the natural environment. The size of the stones and rocks have to in line with the size of the aquarium. It is important to use a wide variety of sizes, just like in nature can be found. Also, dead tree roots can be used in this step to build up your hardscape, if it matches your biotope.


As substrate use sand or gravel that match in colour with the natural environment. Sometimes it is needed to combine different types of substrate to mimic the natural habitat. Always try to elevate the substrate in the back. This way you achieve depth and perspective in your aquarium or paludarium. You can also use coco peat blocks to build land parts in a paludarium. The benefit of coco peat blocks is that plants can root in it and it holds water for a humid environment. But be aware that if you use coco peat blocks the water will be brownish (especially in the begin) and the pH will be more acid.

Softscape design

The final part, the softscape design, consist of planting the enclosure. Select plants that are close to the plants that grow in the natural habitat. It is good practice to plant more plants of the same species together. Also, do not plant too many different species, because this will affect the natural look of it. For inspiration about biotope aquariums and paludariums, I advise you to look in the library of the International Biotope Aquarium Design Contest. Here are hundreds of contestants recreating real biotopes. Every entry has a description of the aquarium and its species (fish and plants), used equipment, water parameters etc. It can be very useful to plan out your biotope aquarium or paludarium.