Quite a few people recommended Warner Marine's EcoBak media when it comes to nitrate & phosphate reduction in the aquarium. This was one of the first brands to come to market initially, and for a period it was almost always out of stock. If you've been on the fence, unsure if it is worth the effort, let me assure you that it replaces other choices like vodka dosing... and it does so nicely.
Biopellets need to be run in a specially designed reactor. Two that I've used are by NextReef and by AquaMaxx. These reactors force water to flow strongly through the media, causing it to tumble at all times. Water shouldn't channel or flow through clumped media, and using the right reactor will assure that it moves adequately.