I am using the DR.fosters/smith brand cheaper then prime, have noticed no difference.
Need to compare on equal footing
Fosters Chlorine Neutralizer...................2.5 gallon treats...19600 gallons......$56.45 (5 64oz bottles at sales price of $11.29)
Prime ...............................................2 litter treats up to 20,000 gallons....$36.99
also Prime says "Provides essential ions and stimulates natural slime coat "