He's probably a bit over 1.5 feet long at the moment, and he's growing at a fairly steady pace. I'm afraid I didn't measure him when I got him, but he's easily doubled in size since then. I figure he's growing an average of 1/2 to 3/4 inches a month, although without actually measuring him it's a bit hard to tell.
The actual size is a bit of a guess right now too, as his tank has a fair amount of driftwood, and I usually only see parts of him at a time, but based on where everything seems to be compared to him, and the few times I catch a full glipse of him, that seems about right.