I certainly not going to argue with people that have so much more experience than I.
My experience with Flourite has shown me however, that it has not changed my water parameters in any way from my tap water. When I first started with plants, I expected the Flourite to supply the nutrients in a low light tank. All my plants were dying until I started dosing iron and potassium. They didn't start thriving until I put in root tabs.
That was my reasoning to state it is inert, basically.
Wouldn't you like to beside the seaside?