Candystripe Plec (l015) are omnivores but they prefer more meat in their diet than vegetables. Sometimes they're mixed up with clown plecs (which do prefer algae and other vegetables) which may lead to that quote of yours....
Candystripes DONT do a good job for Algae, If you want an algae muncher go for a bristlenose plec or a bulldog plec. Or, if you have a large tank with lots of wood, a group of 3 clown plecs may do well..