2 trays enough to treat one hive.
Place the open tray centrally on top of the brood frames, gel side up. Ensure that there is free space of at least 0.5cm between the top of the tray and the hive cover board, for example, by placing an eke or an empty super on top of the brood box, if you are using mesh floors please fit the floor insert. After two weeks replace the first tray with a new one. Leave the product in the colony until the tray is empty.