Things that can affect semen volume are genetics, diet , age and hydration
Age and genetics can’t be change but diet and hydration.
Eat healthy products , massage the scrotum and exercise regularly because it helps to increase testosterone level which will enhance volume of semen.
Few things you can do:
Take amino acids supplement like L-Arginine ,L-Lysine , L-Carnitine and also zinc which helps increase the volume.
Pumpkin seeds also is good.
