I found several 10lb bags of these at Home Depot today on sale for $5/bag. I bought a bunch thinking I can always return it if not good. I was thinking of starting a 29 gal planted with this as an alternative to eco-complete. I don't like that it is not a dark substrate, but it is much cheaper. Anyone tried using this before and if so, how effective is it? Should I use by itself or mix with sand? Any opinions?