Better To Have As Fish Waste Etc might get traped in DSB etc..Haha..some fish need..Constant flow thru the gills Example are Angles ++better you get bro..your return is just nice put.you might run into Trouble later on.. Nitrates, Phosphates,Algae Growth,Ditrius Collecting, Exchange Of Gases And PH Swings..Also Dirt Will clump in rocks..
Hope i helped!
cheers!