You posted this a while back...
Thanks for the help guys I think I isolated the problem to poisoning from soap or something being absorbed by my open salt bag in the kitchen everything is better now and I just completed my PWC with different bucket and different salt lost one the others pulled through
If your salt wasn't sealed up air tight, it could have absorbed all sorts of stuff that may be testing as nitrates. I wouldn't rule out the fact that you're still seeing the results from this bad bag of salt.
As long as the PWC
water is the same temp/salinity as your tank water, I wouldn't see a problem doing 25% water changes every 3 days or so until those nitrates get down to below 5 or so. Then go back to your normal routine and see if they come back. With only a couple cleaner shrimp and some inverts, you have no real bioload and even if you overfeed the shrimp I think you'd have trouble getting nitrates that high.
Massive water changes should bring those phosphates down too.