No one in the whole world I'd rather keep this rock for than you, Chuck. They are large. It depends on how you want to place them, of course, but the large piece set in the corner reaches up into the tank to probably four or five inches under the water surface in a 24 inch high tank and extends a good couple of feet toward the middle. The smaller piece is more flexible in terms of placement, but is a couple good feet with lots of cool branches. I will send you a PM. John PS. Does a "couple good feet" sound like "the better part of"?