'algae-producing' originates from the noun 'algae' (from Medieval Latin 'alga', meaning 'seaweed') combined with the present-participle form of the verb 'produce' (from Latin 'producere', where 'pro-' meant 'forward' and 'ducere' meant 'to lead').

'algae' entered English via Medieval Latin 'alga' meaning 'seaweed'; 'produce' comes from Latin 'producere' through Old French/Medieval English; the compound 'algae-producing' is a modern English formation combining the noun and a present participle to create an adjective.

Initially, 'algae' referred specifically to 'seaweed' and 'produce' meant 'to bring forth'; together in modern usage they have come to mean 'causing the growth or accumulation of algae'.