I have fed the AM400 and really like a small amount mixed in with the larger feed to feed the sub 3" BG. A bag will last me all season because the tiny pellets go a long ways.
It is hard for me to get it though. Much easier to order the largest size Optimal starter and get it delivered to my door.
Around large fish farming areas it is probably easy to get any of the Purena feeds. Out in the hinterlands, not so much so.
