Care
When recieving isopods, make sure to give them some fresh air when they arrive and then leave them in a warm, low lit/dark area and give them a day to acclimitise.
Isopods are very easy to look after and will thrive when they are given the right environment, so getting this right is very important. Isopods breath through gills (like fish), so it is imperative that an enclosure never fully dries out. They can get on fine in damp conditions and even fairly dry conditions but never completely dry.
Substrate should be made up of something moisture retentive (sphagnum moss/coco coir/etc) and an untreated organic element (organic compost, untreated rotten wood or woodchip, etc). Organic premixed and springtail-innoculated version here: https://tealtropics.co.uk/product/magic-mix/
Enclosures must be sealable but have plenty/a few big air holes cut out to ensure a fresh supply of air. A moisture gradient within an enclosure is highly recommended–this is where you have a ‘dryer side’ and a ‘wet side’ so that isopods can go wherever they prefer. This can also be used to gauge what conditions your isopods prefer (they should generally be happy throughout, if they only stick one or other side it indicates their environment should be adjusted one way of the other.
Isopods can be kept in a sealed terrarium (as long as there are plants to cycle oxygen), but it is recommended to do this in larger terrariums (at least 25x15cm) to ensure there is enough food and oxygen available.