Well, I used prime before but de-chlor was on sale so bought some of that. Besides, prime rids ammonia which the good bacteria need. Anyway, I only asked this info because of what I was reading on a subject thread on a diff web page "Convolutions of pH in Fresh Water Aquariums" as well as other sites and became confused. If I didn't need to buy a dechlor product then what was the sense of spending money on something not needed? One less chemical in the water. However, I don't want to change something with out input from others. Appreciate the thoughts.