"Homogenous mixture". Now that's an impressive description...
. I'm using what appears to be a similar substrate in a few of my tanks and I'm happy with it. These two tanks are less than a year old though
. I am experiencing a "mild" cyano outbreak in one of the tanks but I haven't measured phosphates. There's too many other variables I would suspect but as I said, it's mild. I'd go with it, but I'm not a supporter of sand beds. I prefer the crushed coral substrate, it's worked for me.
I wouldn't "sterilize" the sand either. Provided the water isn't stagnant it should be fine, dump the water of course...