Agree with Wizzard. I bought Turface MVP (MPV?) about $14/50lbs too. Bought two bags, remove the small particles (<2mm), still left half bag. Cover 58gal tank (4.5 sq feet) between 4 to 6 inches height. So, I use about 60 lb and discard another 40 lb.
Search your local Reed Perrine store on google, you may find one.
My amazon sword is the first plant in the tank, and it grows one big leaf every 2-3 days. I don't have co2
injection and light is about 1.8wpg.