There is no scientific evidence that adding bottled bacteria to established tank is of any benefits. It might be useful to cycle tank initially.
Best source of bacteria in post cycled tank is fish poop, live rock, coral frags, snails, crabs and other live critters you buy from LFS or online vendor.
Best source of bacteria in post cycled tank is fish poop, live rock, coral frags, snails, crabs and other live critters you buy from LFS or online vendor.