The Seachem substrates are high porosity, high CEC. They can grab and hold minerals from the water for easy access by plants. They do not come pre-fertilized other than with large amounts of iron which is part of their nature. Inexpensive gravels lack that CEC.
Write Greg Morin (owner and CEO of Seachem) and ask, don't take my word for it.
Seachem substrates are well worth their price - I do use them and am quite pleased with them, but I know better than to think that they are by nature or by addition pre-marketing, "fertile". That is quite simply not true.
Write Greg Morin (owner and CEO of Seachem) and ask, don't take my word for it.
Seachem substrates are well worth their price - I do use them and am quite pleased with them, but I know better than to think that they are by nature or by addition pre-marketing, "fertile". That is quite simply not true.