P - Phosphorus GANS
You can basically produce Phosphorus GANS with the Caustic (NaOH) or CO2 GANS Method or you can use the Replication Unit to make Phosphorus GANS-water.
Sources:
Pumpkin Seeds are a natural source with Phosphorus too (but also have other elements in it too). Look for other natural sources too. A possible way is to buy naturally, organic pills, powder or liquid in the pharmacy.