A minimum of a 4ftx45cmx40cm tank for an adult. Preferably a 4x2x2ft is best especially if the bluey is longer than 45cm long from head to tail.
Can live with just a basking lamp, they can thrive without UVB provided that you supplement with vit D3 in their food and give them 30min of outside time every other day or once a week. Basking spot should be in the low to mid 40s, hot end 32-35’C, cool end at 25-27’C. Humidity should be 30-50% or 40-60% depending on the subspecies and locale you get.
substrates that handle moisture are best, I prefer euci mulch or a mix of euci mulch and coco fibre, I don’t recommend coco fibre by itself because of how dusty and powdery it is when dry and it can cause eye irritation. Aspen, straw or something similar are ideal to add in a corner or digging box for burrowing and especially good for brumation, they aren’t good base substrates because they can‘t handle moisture. You can buy euci mulch from bunnings in big bag for 8-9 bucks, any brand doesn’t matter.
2 or more hides PLUS plenty of foliage and cover. If the tank is too open and bare, the bluey will be more flighty and not come out as much. Do provide a lot of enrichment like branches, rocks etc; and change it up each time you clean the tank.
I recommend feeding them a mixture of high quality/grain free dog food and greens/veg as it’s more nutritionally complete and contains cartilage, organ meat and bone that normal minced meat meant for humans doesn’t have and skinks do benefit from this stuff. Alternate 3 different brands/flavours and also have some vetafarm lizard food to ensure they have plenty of protein variety. I personally don’t include fruit in their mixtures unless they’re being picky, it’s like putting lollies in a salad, I keep it as a treat only by feeding them outside of their main meals. Babies (0-3 months) should eat everyday, juvies (4-8 months) every 2nd-3rd day and adults (9-12+ months) about once or twice a week. Young blueys need higher protein and gradually increase vegetation as they get older.
I recommend reading more care guides, more info is always better because one care sheet is one person’s experiences and their methods may or may not work for you. Other really good sources of blue tongue info are ReptileMountainTV, coop‘s reptiles (both on YouTube) and reptifiles.