any sump either diy or store bought .diy alot cheaper do a simply search on sumps you will get all kinds of diy info.better for bio and adds more gallons to ur system.ex.155gal tank 30gal sump u got a 185 gal system.and u can hide stuff in there to like heaters.as far as wat kind of sump trickle,submerged ceramic,fluidized bed/bubbler 1 its just prefrence.i like this he likes that and so on they all work very good hth goodluck