Upside down jelliefish are not like others, but they need light and no live rock or other objects to catch on, or tear the bell, the normal position is upside down with the zooanthellia algae facing the light, they rarely move, and they are not easily maintained, but not impossible. The main problem is they need the same set up as a reef, but with no live rock or corals or fish. The cost vs the look isn't really worth it in my opinion, but for you it very well may be and I'm not the one who is going to spend time at your tank so go with what you like, you probably would not like some of my tanks, I have a plan to make a cave tank with copper sweepers like I have seen in the ocean, very boring but something I have wanted to do since I have seen an outflow pipe with hundreds of them in the entrance.