1 tang in a 75 is pushing it. the inch per gallon rule doesn't really apply to marine fish. most tangs will reach or exceed 8" in length (some up to a foot and a half). it can be done though with keeping pristine water quality and increasing flow immensely. keeping a fish alive and that same fish growing and thriving in your aquarium are 2 different things. im not trying to start anything here but it is irresponsible to keep 5 tangs in a 90 gallon tank. those hepatus tangs should reach a foot a piece, assuming they don't die first, which combined is half the length of a standard 90g.
"Someone else does it" is never a good reason to anything.
A two week old 75 is no place for a tang. Honestly. These fish are wild, and of limited supply...they deserve our respect. I mean this with all due respect to you. Do right by these animals...and enjoy them when you can provide better for them. You'll be happy you did.
IF you do get a tang, stick to one, and stick to the smaller species. One yellow tang wouldn't be a terrible idea.
i don't mean to come off in a mean way but seriously man. don't do it to the fish. you could probably live in a small bathroom but i don't think you would like it very much. you could keep a great dane alive in a small studio apartment but is it fair to the dog?
adam is right, a yellow tang 6 months down the road is probably your best bet if you have to have a tang in there but stay away from the hepatus, powder blues and browns, nasos etc. even though its possible, like keeping a bengal tiger in my basement, its not a smart responsible choice.
for one its not a two week old tank its a 3 year old established tank for on and the yello has been in there from the get go along with 100 lbs of live rock.. and i have a hepatus i got a month ago thats 3 inches and gets along great with the yellow.
I would pass on the tang. I had 2 in my 75gallon at one time and it was a mistake. The Hippo tang grew from 2 inches to about 7 inches in a few years there simply wasn't enough room in the tank for that big of a fish. The other tang was a white faced tang. I had to get rid of him after he grew bigger and picked on the hippo.\
The hepatus or hippo tang starts out small, but if you want to see what size they grow to, visit the omaha aquarium and you'll see a bunch of them 11+ inches in size. and probably an inch thick. These things get big!
I'd say get a 6 foot long tank if you are looking for tangs. A nice alternative could be a dwarf angelfish. Though you may need to be careful if you have corals or clams in your tank.
For 1 you signature says "75 gallon 2 weeks"
Second you asked for the advise!!!
Your tangs may get along but you WILL be sorry when they get stressed and die on you. A 75 is TOO small for 1 tang letalone 3
As said these are beautiful animals and need better care than someone sticking them in a 75 with 100lbs of rock!!
Can the tangs you have now even turn around? Please for there sake do some reading and respect the aminals needs!!