Hi Peter, I did not want to go into to fine a detail as its a forum, however in my store I professionally quarantine all my animals. I have very strict protocols in place to eliminate as much as possible possible transfer or build up of bacterial pathogens (vibrio etc.) in the salt water I use for my animals. I have not witnessed the brown covering in the bio secure vats I use for my animals water. Only in the VATS I use for pre mixed sale.I have recently cleaned my saltwater mixing container and not had the issue again in 3 weeks since.
Curious why you think it’s bacterial and shouldn’t there be something we could use to offset it?
I also notice a bio film build up on the vats that are not sterile and a smell that would make me think, bacterial or chemical reaction / bacterial.
I am in no way suggesting that my conclusion is related to all of the cases discussed so far. I just wanted to add a little more anecdotal information in an attempt to find a possible cause for the reaction some are noticing.
I would also like to point out that I only use Reef Pro because it meets my particular needs. I am in no way trying to promote the brand. Also I try to get my customers to stick to one brand and not keep blaming salt brands for their problems. In my experience salt mixes are all equally good at maintaining a healthy environment for the animals. Also I can pick my salt up from the warehouse, 2 hours drive so always have it available.