I have used DrTim's One and Only twice with excellent results. While some folks have given me positive reports regarding Stability, I have never used it nor even taken a look at what is in it. I finally went to the SeaChem site and read their info on the product which they claim works in both sw and fw.
When I was done reading I went to their contact page and sent them a message. It basically said their info was mostly incorrect and they were putting the wrong stuff in the bottle for fw use. I told them that I have liked and used their plant additives (Excel, nitrogen, potassium and phosphorus) for over a decade but I would flush a free bottle of Stability before I would add even one drop to any of my fw tanks.
This product may be of benefit to sw tanks, I don't know. But it has no place in fw, imo. If their claims were true their biggest business would not be in aquariums but in waste water and drinking water treatment because they would have developed the miracle bacteria mix these industries have tried to find for decades.
In a nutshell, bacteria that thrive in high ammonia environments don't do so in lower level enivirons and vice versa. Moreover, if the discoveries over the past 6+ years regarding ammonia oxidizing Archaea in the ocean are correct, it would indicate they, and not bacteria, are the primary ammonia oxidizers in sw. They don't list Archaea as being in the bottle. So how good might it be for sw if that research is correct.
Finally, if you use DrTims or Tetra's Safe Start, neither tell to dose the product for 7 days in a row. One dose is all it takes. Now they do say you could add some after water changes or when adding new fish. The first is clearly a sales gimmick and the second makes some sense in some cases. Why are the bacteria need able to come out of the Stability bottle in one dose? Could it be you have to buy 7 times as much? And of course Sechem suggests " For optimum biofilter performance use 1 capful for each 40 L (10 gallons*) once a month or with each water change and whenever introducing new fish or whenever medicating an aquarium."
Come on folks do any of you believe that takes a monthly dose of anything to keep the biofilter in your cycled established tank optimal

?