Yep, agree with mr x. They can move about your tank at will, you have absolutely no control over where they go. They are known to get sucked up by powerheads, filters, overflows, anything they can get stuck in is fair game. I was also scared of it eating my fish, the nem when I returned it was 1/3 the size of the tank, took up the entire left side. everything avoided it and I had to place my corals far away.
The other consideration was that my tank was new and not established enough for my liking. It was an impulse buy on my part that i shouldn't have made.
good luck though!
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.