Inorganic matter – also known as Crude Ash or Incinerated Residue – is a legal term that all pet food companies must declare on their label. It is not an added component, it is simply the amount of minerals present in the food, as determined by a set analytical technique.
The usual method for determining Inorganic Matter in a pet food is by the incineration of the sample. This leaves behind a residue and it is this residue of minerals that gives the Crude Ash content.
By their nature, fish and algae are both high in minerals which your fish require for growth and good health.
For more information on rules and regulations of pet food labelling, please have a look at the Pet Food Manufacturers’ Association webpages;