It takes at least a couple of weeks to settle, with the added reef salt and everything. Then I was going to purchase jellyfish - and found out that they actually cost more than 50$ a piece, because of overnight shipping (from Germany, I live in Denmark).
So I started doing some research on the tank, and read about 5 horror stories about how they always died within 3 days, even after following instructions very accurately.
I later emptied the tank, and now it's sitting in the attic.
Build quality is decent, but not perfect. After sitting still for about 3 months, the top lid started bending/skewing quite a lot, now it almost doesn't fit anymore. It's also quite noisy, not something that you'd like to sleep in the same room as.
If anyone wants a jellyfish tank where the jellyfish apparently dies within a couple of days, I have a cheap one for pickup here in Copenhagen.