That particular freebie, BioS, is not probiotic bacteria, it is nitrifying bacteria and would be good to use for someone that's just starting their tank. The NP Pro that comes with the probiotic salt is not nitrifying bacteria, it is probiotic bacteria (the same that feeds off biopellets) which lower nitrate and phosphate.
Instant Ocean often has a tshirt in the bucket. That doesn't mean you have to wear it.
