When I started looking for food and asking what others used, someone had mentioned that they like Ultrabalance, so I started looking for them and who had it, and it turns out that it's made about five miles from where I live. So I buy a 22 pound bag for about $45...even cheaper if I go through the local feed store since they now realize they can get it (they told me they couldn't before).
The fish are very healthy, it seems, and the koi were about 4-6 inches two years ago, and are now about 14-16 inches. The wakins grew a couple inches this past year, and one shubbie grew about 4 inches. I can't really say it's "good" because I'll never sample it, but the fish are growing!