'algae-limiting' is a modern English compound formed from 'algae' + the present participle 'limiting'. 'Algae' comes from New Latin 'alga' meaning 'seaweed' (borrowed into English via scientific Latin usage), and 'limit' derives from Latin 'limes' meaning 'boundary', via Late Latin/Old French.

'algae' entered English from New/Modern Latin 'alga' (used in scientific Latin) and became the plural form 'algae' in English; 'limit' evolved from Latin 'limes' → Late Latin 'limitare'/'limitat-' → Old French 'limite' and then into Middle/Modern English as 'limit' (verb and noun). The compound 'algae-limiting' is a recent formation using 'algae' + '-limiting'.

Initially the components referred separately to 'seaweed' (algae) and 'a boundary or restriction' (limit); over time they combined into the descriptive compound meaning 'causing a restriction of algae growth', a specialized ecological/technical usage.