how often to put salt in koi pond

Quick Answer Use plain, non-iodized salt — sodium chloride (NaCl) with no additives — never table salt with iodine or anti-caking agents. For general support, 0.1% (1 lb per 100 gallons) is a common ongoing low dose. For treating parasites, 0.3% (2.5 lbs per 100 gallons) is the standard therapeutic concentration, added gradually over 2-3