Never had a problem with Prime making the water foam, or bubbly. The most cost effective way to go is mixing your own dechlor using sodium thiosulfate. The only problem is when you are dealing with chloramine. Chloramine breaks down into chlorine & ammonia, if you have a well cycled tank with plenty of bio filtration, it will deal with the ammonia released. On a more recently cycled tank, or one with fry or more sensitive fish stick with a brand name like Prime or Aquasafe to take care of the ammonia as well as chlorine & chloramine.