Well in that case I'm hoping the rock and sand will be plenty for the pair of clowns and a few inverts going in the tank
Unless you have a tank crash or something large dies and doesn’t get removed I’m not sure it’s possible for ammonia production to exceed the ammonia/nirtite processing capacity of even very modest rock quantities.
About the only scenario I can see for bio balls might be for an LFS where they often run temporarily heavily stocked tanks with no rockwork.
I have a 10g QT tank set up but dormant for a month or so. I’m going to try an experiment on it to see if a golf ball sized piece of live rock (from my main tank sump) can process 2ppm ammonia in a reasonable timeframe with no lighting or any other cycled media.