I bought a bag of red Flourite and found out that is is very dirty, I mean very dirty! And I donot see the justification for the price and doubt it benifits, despite of many people here claim otherwise. Here is why.
1. It is just crushed shale and slate, both are mud stone, with the latter...
I found pretty interesting micro and macro deficiency in plants it is not for aquatic but it give you an idea how they interact each to other.