

Fresh Water Standard, Hard (160-180 mg/L) by Exaxol, catalog numbers T70404-1 and T70404-4, is a synthetic hard fresh water standard with about 415 ppm TDS and hardness of 160–180 mg/L as CaCO3, matching EPA hard reconstituted water. Available in 1 L and 4 L from MBP, a registered vendor to many research institutes across the USA.

