These were from koistop.com. I got them in 2008 and they were about 7 to 8 inches, now they have doubled in size.  I had them in two mud ponds I made myself and fed them only twice a day during spring, summer and fall.  The winter can be cold here -- North Carolina (USA) but my koi made it!  The best growing size was the showa and the best quality was the ginrin kohaku. My koi are the best around the block!