The chunks are definitely larger, however, I don't thaw first and just roll it between my fingers to break it up in the the tank. Any large pieces I miss is usually taken care of by the nem or snails and crabs. I might be wrong, but I don't think the "nano" blend has any algae, broccoli, etc. in it in case you have any fish that eat that as well.Word of caution on the reef frenzy, unless you have large fish, i.e. 6+ inches go for the nano as the chunks in the reef frenzy will be too big.