Retest no3 and po4 and get a real number. No3<5 po4<0.1, which I assume you meant not <1.
How many fish, I see 2?
Feed the fish more and no3 and po4 will rise. Running both at close to 0 is ok but you have to feed and test more to get the numbers where you want.
It wont happen on its own.
What forms of nutrient control do you currently do?
No3 and po4 are what your export system is not removing.
Do you run a skimmer, carbon, sump?
What do you mean by letting ca and alk level out? They need to be stable in order for anything to grow.
Knowing all the above will help everyone to understand your system.