I think it's a copyright on how to make it stay active in a bottle. I read an article awhile back that said there was another company that used to sell the bacteria, but it had to be refrigerated. Apparently Tetra bought the company and then found a way to make it stay active without refrigeration.It is frustrating, how can a company have copyrights on bacteria that occurs naturally in nature? I use Stability and it advertises it contains a mixture of aerobic, anaerobic and facultative bacteria which facilitate the breakdown of waste organics, ammonia, nitrite, and nitrate.