I’d imagine that IO has better margins since it’s the cheapest salt! Freights kills any margins coming from over the pond and raw material when sourced through purer sources typically have smaller margins than those naturally found because of protection clauses. I see it with car wash chemicals and it’s a pita to compete with dirty hydroxides that most people dump on their driveway.
This is complete conjecture, not proof.
So the marketing company that sells expensive salt said you should use expensive salt? Imagine that…
It’s fine to have your opinion but don’t present it as fact…
Is ‘sending it to a lab’ mean you got an ICP test?