I don't know if it has any purpose or not, but if there is a purpose it definitely is not listed in the quote from the original post.
Parts of the description don't make any sense, and the parts that do are impossible. There's probably more than .o6mA of electricity being introduced into the water by the flourescent lighting and pump impellers anyway.
Iron etc. bound up into a complex structure forming a gemstone isn't likely to be useable by aquatic plants. There are minerals like these in the glass that the aquarium is made of.
This is the type of language you see in an advertizement for healing metal bracelets, or energy crystal pendants.