I am stocking a new pond wit FHM, CNBG (1-3"), and RES (1-3"). I will put some larger BG and RES in over the next month, as well as some CC (3-4"). It looks like I should be feeding Aquamax 400, but I might only be able to get 600 locally. What size would those with experience recommend? And would 600 work?

I would use Aquamax 400. If they have Aquamax 600, they should be able to get 400.

I recently got the fry feed for SMB 4-6" long. I should have gotten the 400. You probably should too or maybe mix 400 and fry.

Agreed with the 400. Your fatheads would probably hammer (peck at) the 600, your redears probably won't feed on artificial feed at all, and of course 600 is too big for your CNBG's. So CNBG's will make it through the winter in Virginia?

I started my pond with almost the exact same size fish. I used AQMX 500, as that is what Todd Overton recommended. I fed that exclusively for 1 year, then went to 500 and 600 mixed equally.

Now after 4 years I feed a mix of 2 lbs AQMX largemouth and 5 lbs mix of 500/600. I bought two large barrel bins to mix/store them in.

A word of caution, since we seem to have started out about the same way. I assumed that my pond would be empty (fishless) when I stocked it because it cannot receive drainage/overflow from any other source (high sides to add depth). I stocked all fish in Oct 2007 (pond dug in Feb 2006) and began feeding not long after. I noticed that there seemed to be some fish larger than what I stocked coming to get feed, so I put a worm on a small hook and proceeded to pull out a 6" green sunfish (I did not know this until the PB experts weighed in). Todd suggested to keep fishing and buy a fish trap to see just how many of these things are in there. After 1 month we had caught/trapped over 250 GSF and 7 catfish, some as big as one pound. I was not seeing any of my stocked fish in the trap, so I had to go back and restock, but went with larger 3-5" CNBG and RES. Moral of the story, if you haven't been fishing because you thought there was nothing in there to catch, start fishing with a mid size hook/worm/shrimp and see if you get anything.

Sorry for the long story....