We have been using Aquamax for years now, both the 500 and 600, but our dealer said that he could no longer get it, no possible dates in the future were given to him, so we had to switch to the Game Chow. Still a good food I suspect ( still expensive, albeit not as much as the real thing ) but I have noticed a distinct last of oder compared to the other stuff, it was very "fishy" smelling....this stuff....not so much. We are way out in the Ozarks of MO and have very limited dealerships available to us within driving range, but when I called the only "city" to speak of 120 miles away, they told me the same thing. Wish the news was better, sorry....