Both are at Zero. Of course that is with tests that have limitations. I use the Seachem Nitrate test and the Merck/Deltec PO4 test. I know these are present to some degree because I have macro alga in the system, but they are using up most if not all of it. Right now my macro is in decline so I can believe the test results without too much skepticism.
As far as starting a system over due to poior water quality, I find that difficult to swallow. For me, with my size system, I can't imagine doing that without exhausting all other options first. Really, if my levels started to elevate, I would look at several issues:
1. detritus...get rid of it.
2. water changes: increase to lower levels
3. RO/DI water: check to make sure systems are running well and I am getting ZERO TDS. When I see 1 ppm TDS, I fix it!
4. Water flow? Is the flow slow or slower than it was? Do pumps and plumbing need to be cleaned?
5. Bio-load: Do I have too many animals for the water volume?
6. Overall water quality: Are my inverts dying off? Snails & Hermits OK?
7. Lighting: Do my lamps need to be replaced?
These are just some of the potential problem areas. You are welcome to PM with more discussion too!