Welcome!
Firstly, please read the care-sheet.. and I we mean 10 whole times.

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http://bluetongueskinks.net/care.htmFerret-food, huh? Ferret-food is made mostly like cat-food, but with an added ingredient, which has left my mind. I probably wouldn't say that it is harmful to the skink, but can be in a degree of over a long period of time. Dog's diet are more closer than JUST meat eating carnivores such as ferrets, cats, ect. A lot of people feed dog-food as the staple part of the protein portion of the diet. Some feed turkey, some beef, some even kangaroo. I would stray away from chicken or pork as being the staple. If you do feed, make sure you supplement calcium+D3 with it. I personally supplement every feeding, but people are successful with every other feeding. Please read over this thread, and mainly focus on the third comment, which is basically what mine is:
viewtopic.php?f=24&t=2038730 gallon is WAY to small for a skink than can potentially grow up to be 26". That would be like living in a closet your whole life. Not fun. 3 x 2 is fine, but with Meraukes being the longest species, it may cause a problem. I house all my adults and sub-adults in a 55 gallon enclosure, which is long, but not very wide. I plan to do a DIY with turning them on their side, which would being perfect then. Right length and width.
--oh, and if you didn't take the hint.. you have a Merauke. One of my favorite species of Tiliqua.
Some headers, Meraukes are not very forgiving when it comes to humidity, but your substrate seems absolutely perfect. Good for holding the moisture in. Try to get at 50%-60%, though they have been found in almost 100% humidity.
They are a very warm temperature species, so around 80 ambient is fine. I wouldn't go over 80, and no lower than 70 during the day. They do not require a super-hot basking spot like some of the Aussie species, I usually keep mine around 95. I have noticed around 100-105, they never seems to bask.
I don't think I can think of anything else, right now. Congratulations on the new skink.
"The love for all living creatures is the most noble attribute of man." — Charles Darwin