This is just me but I think a 160 is kind of small for a Blue Tang. I would do a smaller Acanthurus like a Lavender, Japonicus, and maybe a few others. But I think 3 Tangs is the maximum I’d do in a 160. Six Lines do have a reputation for being nasty, though I’ve heard of exceptions. I’d check.
Why not a Regal Angel in place of the Blue Tang? Lol. They’re being captive bred by Bali Aquarich and Biota is starting to sell them.
Other than that, a 160 can fit a good number of smaller fish. It depends on what you like so have a look. You could put a few wrasses like Fairies, Flashers, Halichoeres, and Leopard Wrasses (more difficult).
I’d also do a pair of Centropyge dwarf angels of your choice (you’re talking to an angelfish fan). If you want to go the easy route, get a pair of Biota Coral Beauties.
You could also consider the slightly larger Genicanthus angels like a Bellus, Spotbreast, or Watanabei, maybe even a pair.
Basslets, Cardinals, some of the more peaceful damsels, and of course the *obligatory* Clownfish pair are all options.
If you are considering Dottybacks, consensus has it that Orchids and Sankeyi are among the most peaceful and are readily available captive bred.
Gobies, Hawkfish, Blennies are all options for fish that use the rockwork.
You could even consider some Anthias. My personal preference is for larger species that don’t do big shoals. I’d be tempted to do two Borbonius or Sunburst in your tank.
Copperband Butterfly (not easy), deepwater Roaps butterflies (Mitratus, Declivis, Burgess, no more Tinker’s because….. Hawaii), Atlantic Longnose, a Yellow Pyramid or Zoster Butterfly.
Some of the more peaceful damsels, you can get a few. To my knowledge they prefer to spawn in pairs although people keep them in groups. Azures, Talbot’s, Rolland’s (get the Vanuatu variety, the others don’t have that yellow cap and are kind of bland), Tracey’s, Tricincta (don’t mistake it for the Dascyllus), Starcki are IMO the best. I’m not a big fan of Chromis.
Maybe a Foxface, if you can find a Magnificent or Fiji Bicolor they’re a bit more exotic than the yellow ones.
Just laying out the options and I’m not saying include all the fish. If you want to cut back on bioload, I would have 3-4 larger fish and call it a day, and fill the rest with smaller / medium fish. This might mean scrapping a Tang or two, but then I’m somewhat biased as Tangs aren’t really my favorite group.
*I am personally somewhat against “pairing” butterflies as to my knowledge their sex is fixed.
