Lets not turn this into one of those threads. I'm sure there is some benefit to using this in aquaculture the same way kelp meal is used or why would these fish/shrimp farms use it. I agree with Tom in the fact that these minor trace elements are not that important but for me it's all about trying to find a cheaper alternative for dosing and the fact that it's natural is a bonus for me.
Azomite that they used as feed supplement according to ingredient list on video, made no mention of lead,mercury,arsenic, that appear's on list of ingredient's if you just google content of the azomite.
I think this makes sense,not many folk's want to eat fish/shrimp that have ingested the lead,mercury,arsenic.
Maybe is different formula for plant's,crops,than what is used in video as feed supplement or...they convienently left out the lead,mercury,arsenic.
My brother has some of the azomite left, and while I might give it a go in plant only tank in the future,,I don't think I will risk trying it with my fishes,shrimp's no matter how miniscule the proportion of offending ingredient's.