Sterilize in Schott closed bottles 20 min at 120 C. Age for minimum 3 days
to allow precipitate formation on the bottom. Carefully decant clear
solution to another sterile bottle.
After sterilization:
4 mM NH4Cl from 2 M stock
40 mM sodium thiosulfate from 2 M stock
1 ml/L trace metals (Pfennig&Lippert, 1966)
1 mM MgCl2 x 6H2O
White cloudy presipitate forming after Mg addition can be dissolved by
vigorous mixing.
