Freshwater isopods are rather hardy and easy to keep and therefore ideal for a jarrarium setup. You can use any glass bowl or jar with a capacity of at least 1 gallon (5 liters), with a wide enough mouth (avoid “bottlenecks” and opt for mason jar -like containers instead). I use these 1-gallon glass jar made in USA with a 4-inch mouth, but you should not have any problems finding similar containers wherever you are located. Make sure to opt for transparent containers with a smooth surface and no glass decorations, so that you can have the best possible overview of what is going on inside your jarrarium.
Ideal substrate and vegetation for freshwater isopod jar
We are gonna try and replicate the original environment in which asellus aquaticus thrive – despite being freshwater creatures, in nature you will find these inverts closer to the surface near streams and other water bodies with low currents, as their swimming skills are rather limited compared to other crustaceans. They enjoy living in polluted waters filled with plants and debris that they use for both nourishment and as hiding spots – the thicker the vegetation, the better.
In order to create such an environment in our nano tank, we are going to fill the bottom of the jar with a few inches of mortar sand and humus (which will add nutrients to the soil to aid plant growth). Aim at a bit less than one inch of substrate for each gallon of water. When choosing vegetation, we need to ensure a mix of slow-growing plants that can offer shelter and fast-growing plants that can absorb toxins and purify water. Nearly any freshwater plant is suitable, but keep in mind the short size of your container! I usually opt for a mix of Anacharis Elodea Densa (for shelter) and dwarf plants like Sagittaria Subulata or Hairgrass Eleocharis Parvula for water filtration.
Water parameters for asellus aquaticus
Aged tap water can be used safely to keep asellus aquaticus. After placing just the substrate, fill the jar with water straight from the tap and leave it uncovered for 24 hours to allow for dechlorination. At this point you can introduce your vegetation and wait another 2-3 weeks before inserting your freshwater isopods. These creature can survive in most aquatic conditions and temperature ranges, so what you’ll need to keep an eye on is rather how to make your vegetation happy: ensure minimum lightning and temperatures neither too low nor too high, between 53 F (12C) and 82 F (28 C) should allow for decent, but not overwhelming, vegetative growth.