

Fresh Water Standard, Soft (40-48 mg/L as CaCO3) by Exaxol, catalog numbers T70402-1 and T70402-4, is a synthetic soft fresh water standard with about 104 ppm TDS and hardness of 40–48 mg/L as CaCO3, matching EPA soft reconstituted water. Available in 1 L and 4 L from MBP, a registered vendor to many research institutes across the USA.

