The word 'non-algae' is formed in English by adding the prefix 'non-' (meaning 'not') to 'algae', which comes from Latin 'alga' meaning 'seaweed'.

'Non-algae' is a modern English compound, created by combining 'non-' and 'algae' to specify things that are not algae.

Initially, 'non-algae' simply meant 'not algae', and it continues to be used in this straightforward sense in scientific and technical contexts.