Self-sustaining ecosystems are growing in popularity, with commercial ecosphere and shrimp bubble kits being advertised as an alternative to aquarium tanks that requires little to no maintainance. But that of closed shrimp ecosystems is also a controversial topic due to the ethical implications of keeping a living creature enclosed in such a restricted space. Because of this, many aquarists decide to opt for creating their own DIY self-sustaining ecosystems that require minimal maintainance while ensuring the well being of its inhabitants.
The Walstad Method
The method we are going to describe was popularized by ecologist Diana Walstad, and it is the most foolproof way to create a nearly entirely self-sustaining system for freshwater shrimp. A Walstad tank tries to replicate a natural environment as much as possible and it is also referred to as a Natural Planted Tank (NPT) or El-Natural aquarium. In her book “Ecology of the Planted Aquarium”, first published in 1999, Walstad goes in detail when describing what are the key factors for a natural aquarium setup: there needs to be a balance between fish, plants and substrate – with the amount of vegetation being much higher than the animal population. Think of plants as natural filters that can only purify so much of the bioload generated by animal waste, while the animals will do their part in getting rid of decaying plant matter, ultimately leaving the number of nitrites in the water as minimal as possible. In such a setup, water changes are not required – although the tank still needs to be topped up from time to time due to water evaporation and because plants will absorb it on order to grow.
Find out how to setup a natural planted tank, with a guide written by Walstad herself!
DIY Self-sustaining Shrimp Jarrarium
For a shrimp jarrarium you should use a relatively large container, like this Anchor Hocking 2.5 Gallon Montana Glass Jar. Make sure that whatever jar or bowl you use is made of glass, has a wide mouth, and has a smooth surface with no decorations.
Substrate and vegetation setup
Place the jar on a sturdy table and fill it with a few inches of shrimp- and plant- friendly soil. Spray a little bit of demineralized RO/DI water to wet the soil and set your plants of choice in place. Any dwarf variety of shrimp-friendly freshwater plants will do. Top your substrate with equal amounts of black aquarium sand, partly covering the root of your plants in order to stabilize them. You can then add the remainder of your water until you fill the jar almost to the top. Try to fish out as many floating pieces of soil or plant leaves.
Best shrimp and crustaceans for self-sustaining jarrarium
Caridinas and neocaridinas
The aforementioned opae ula shrimp (also known as hawaiian red volcano shrimp, or by its scientific name halocaridina rubra) is an ideal choice for these types of ecosystems due to their resilience and longevity. Other candidates include the amano shrimp (caridina japonica or multidentata) and the red cherry shrimp (neocaridina heteropoda or davidi). These species do not naturally live as long, but are prolific breeders and will grow in population rather quickly.
Possibly a better alternative to shrimp (and aesthetically similar), scuds / gammarus make an ideal animal choice for your jarrarium. Hyalella Azteca scuds are tiny, hardy, and easy to setup as a thriving culture even in a nano tank. They are also rather inexpensive and easily available. See: list of freshwater amphipods online vendors worldwide.
Freshwater isopods (asellus aquaticus) are incredible no-maintainance creatures that make the perfect guest for your jararrium. As a matter of fact, you could just throw them in an open lid bucket with some water and plants and they would likely be happy. They are abundant in nature, but a bit more difficult to find from commmercial distributors. See: list of freshwater isopods online vendors worldwide.
Suitable tank mates for self-sustained natural planted ecosystems are any beneficial snails who can help stabilize water as well as providing food for shrimp by promoting the growth of infusoria.
Are self sustaining ecosystems for shrimp ethical?
There are a lot of animated discussions on the topic of whether keeping shrimp in self sustained ecosystems is cruel or unethical. And there is: it can be. Most of commercial self-sustaining systems like closed ecospheres and shrimp bubbles are too small for their guest to live comfortably. These bowls usually come with 4 or 5 halocaridina rubra, the hawaiaan opae’ula shrimp informally known as supershrimp because of its resilience. But the fact that it can survive in an enclosed space doesn’t mean it is happy doing so! In the wild, this species of shrimp grows to be much bigger and can live up to 20 years – in a shrimp bubble or ecosphere, it usually shrinks in size after molting and dies within 2 to 3 years. We recommend a minimum capacity of 5 gallons for opae ula to thrive and a natural planted tank setup following the Walstad method for creating an ethical self-sustaining ecosystem.
Ecosphere shrimp death
In small commercial ecospheres, shrimp death often occurs due to a decrease in natural resources. The more time the shrimp spends in the sphere, the least minerals and nutrients it will be able to use for molting which result in them shrinking in size and eventually perish. You can greatly reduced the risk of shrimp dying in a DIY self-sustained ecosystem by ensuring enough room for both animals and plants to grow – a 10 gallons tank setup being the most ideal.