Need help with new tanks perimeters

[Bitchwheur?]

It finished it's cycle about a week maybe a half. My parameters were
Ph-8.
Ammonia- 0 ppm
Nirtite - 0 ppm
Nitrate 5 ppm
Idk exactly the salt, but it's fine I've tested it a million times.I added a fish he's been alive fore a few days, but he's breathing heavy ( he seemed to be breathing heavy as soon as I put him in. Maybe the tank isn't receiving enough oxygen. I was wondering if it has to do with kh, calcium, and (or) phosphate. They only told me to test for the ones I have tested for. The p.h has dropped to 8.0 the nitrates look like they climbed to ten or maybe imbeetweem 5 and 10. My fish looks the same. Do I have to test for these? Are they harmful to fish? This **** is confusing af

 

[JEREMY82]

Kh cal and phosphates will not do that,how long has tank been cycling for ?

 

[Bitchwheur?]

Kh cal and phosphates will not do that,how long has tank been cycling for ?

For about a month, the fish is fine I think I was just worrying about nothing, but thank you for solving my confusions. I was really confused about this.

 

[Bronc]

What is your salinity at?

 

[glb]

Do you have a skimmer? That helps oxygenate the water.