Originally Posted by Greenstreet.1
Taking your time is the key in all you do in this hobby. Anytime.
Sadly I think there is a problem here. I read all your threads and got the following info.
You set up the tank on or about 19 Aug and posted on 26 Aug "1 week into my cycle"
You have a 90 gal
You have had huge nitrate issues causing a ton of algae 1 week ago during your cycle.
You asked about stocking and someone suggested a Yellow Tang in a 4 foot tank (although in this case I don't think its the size that is the issue). The Tang police missed this one (probably because we are so (moderator edit)tired of people saying various tangs are fine in many tanks listed as too small).
Now you have the Yellow tang (Tangs are NOT very hardy), and no surprise, it's not doing well. A week ago you were in the middle of a cycle issue, now you have an expensive fish dying.
"Taking your time is the key in all you do in this hobby. Anytime"
or as someone else has in their signature
"nothing Good happens fast in a saltwater aquarium".