I bought a box of this to add to my gravel 20g long months ago...
Dusty, dusty, dusty. OMG. I rinsed this stuff for ages. It's still dusty. Your plants will accumulate dust on them. I didn't particularly care for the (red) color. I haven't noticed much increase in growth, but, every tank is different.
Putting First Layer Laterite in my tank is one of those things I did as a newb I wish I could take back. The price was right tho...but for the price, I'd much rather use FloraMax or something of the sort.