How much starting library to use for Ion Torrent S5 sequencing?

For Ion Torrent S5 sequencing, the user guide for IonChef/S5 recommends 25-60pM of library for each chip, depending on chip type and library fragment size.

Ref: assets.thermofisher.com/TFS-Assets/LSG/manuals/MAN0016854_510_520_530_Kit_Chef_UG.pdf (Page 26)

I was just told to start with 30pM of library for 530chip, and then adjust from there by looking at the quality of reads and polyclonality. I am wondering: is there a way to properly calculate or estimate the amount of library (in pM) to load onto a chip?