They are only about 10cm now, growing fast. They either tear the pallets up when they are soaked, and the larger one swallows the 10mm pallets whole (surprised me when I saw it do that the first time, but they have massive mouths for there size.
The pallets are not the pleco ones, the ingredients have 'mollusks and crustaceans' as the first ingredient, but that is kind of why I am asking what would be a better food for carnivores.