Well, I see three issues which were already mentioned.
Ammonia should be 0 - if your using an API liquid test kit, verify the rest with another test (ask your LFS to verify the result for you)
160 ppm nitrate is way too high, you need to figure out why it's so high and take the appropriate corrective action
Lastly, a yellow tang really doesn't belong in a 55 long term, an adult simply needs more swimming room than a 55 can offer