some say it works, some say it doesnt.
the one thing i know that will much em up, are peppermint shrimp, get two, they are usually prettym cheap, about $9.99 ea.
i got a shipment of Fiji LR once that had 29 pop-up in a matter of days.
got 2 peppermint shrimp, in less than week you couldnt find aps. anywhere.
another plus about them is they breed like rabbits (A-sexual) thats why i said 2 of them. they provide food for the fish and clean your tank too...what a deal!!!