Most people would tell you a Bristletooth’s fine, and some would go a Yellow’s fine, more on the edge than a Bristletooth. A Tomini, White-Tail, Square-Tail, Twin-Spot or that other smaller one (I think it’s called cf cyanocheilius) would be your best choices. If you get a Yellow, it’s best to get a small captive-bred one from BIOTA and it’ll mean lower stocking levels overall due to activity levels and aggression. Plenty of Yellows cap out at 4-5” after years, often over a decade or two in people’s ranks so it’s more the activity and potential for aggression.
Personally, I’d do one of those Bristletooth Tangs as the large fish, and something like a Dwarf Angel or smaller Butterfly as your two centerpieces. Smaller Butterfly I’m mostly referring to one of those Milletseeds from BIOTA, they look pretty and people have kept them in their reefs with success.
Fairies and Flashers are a hit with many people but getting them as males, which is what they’re often sold as, leads to shorter lifespans and that might not be what you want given the $$-to-lifespan ratio. But plenty of people just love them and are more than happy to get a fish they’ll likely only have for 3-4 years, or less.
Personally I say a 75 isn’t enough for the vast majority of bigger fish, so you’ll be building with smaller fish and the Bristletooth Tang.
Alternatively, I could suggest something like a Genicanthus Angelfish (if started small and female) which BIOTA has the Swallowtail, or some of the smaller “medium” Angels that Poma Labs has that likely top out ~5” in captivity.
A Marine Betta makes a cool centerpiece and it’s a beautiful fish, but perhaps not your best fit if you aren’t looking for a cryptic show fish.
So if I were you I’d do something like:
-Bristletooth Tang
-Dwarf Angel or Milletseed Butterfly
-A Basslet like a Royal Gramma
-Mandarin (get captive-bred, and once the tank’s more mature, the CB ones still primarily eat pods and frozen food or pellets- if they take them are a supplement)
Gobies, Blennies, Clown pair- not a fan of designers, more peaceful Damsels (Talbot’s, Springer’s, Azure), and that’s pretty much full IMO.
I would have suggested something in the Wrasse family but the competition for pods makes me a bit nervous in a 75 with a Mandarin.
Fairies and Flashers maybe, although keep in mind if you get them as males they are likely in the latter half of their lifespans and they don’t live too long as a whole. Plenty of people still love them though and gladly pay knowing they’re getting a fish that lives for 3-4 years on average.
I think Chalk Bass are underrated and ORA breeds them, so ask for CB ones if you can.
Cardinals are underrated too. PJs don’t age well and lose their red spots with age, and keep in mind many species will pair off and only shoal as juveniles. I think a few of the Orange-Striped Cardinals (Ostorhinchus cyanosoma) would look nice.
If you go with a Yellow Tang, you’re looking at lower stocking levels overall. The water column can’t be congested and almost all of it has to be left for the Tang.
