Hi Scooty, I bought it from someone who had a home based frag farming operation, he was shutting it down and selling off everything at fire sale prices, I think he told me he bought it online, I've never seen this at any LFS, but I imagine a few carry it or could get it. I don't remember the product name, unfortunately I didn't keep the bags, but it was part of the Caribsea line. It is all actual coral rubble, none of the pieces are less than 1/2" , most are an inch or more with some chunks in the 2" to 3" range, it came in a 40 or 50 pound bag. It works great for fragging, I've used it for almost all my frags. I actually did not intend to use it for a substrate in my tank, but I have some very intense current, and with the OM-4's it is constantly shifting, just right for moving finer substrates, I also bought three hundred pounds of medium grade araganite intending to use it, when I put some in the tank it was moving all over the place, (I tried oolitic first, that was an underwater sandstorm), hence plan B (anyone want 300 pounds of aragonite cheap???). The rubble never moves, it's quite stable in the current. Another benny is the detritus vaccuuming, we've all seen what a pain it is, tumbling the substrate in the siphon tube, tearing everything up, making a cloudy mess of your tank, yada yada yada.... The rubble almost gives the bare bottom effect, the fine detritus particles aren't embedded in the tiny spaces found within the typical substrate, it can't hide in the large spaces within the rubble matrix, vaccuuming goes much quicker and detritus is more effectively and efficiently removed (IMHO). Another great benny is that you have a perfect habitat for massive pod culture, in my case I now have 27 square feet of optimal pod fuge effect, my system is absolutely infested with the little devils after just three months, Mandarin heaven.... I used an Oolitic DSB in the 55 gal side of my fuges, so at least it didn't go to waste.. But I grow verbose, time to shut up...
Best regards, Joe