most plecos prefer a good current. i think commons were found in systems in florida, but most plecos are find in South American rivers. you dont need a river system as it were just a powerhead to get a flow and a good oxygen supply. although before you start you might want to find out how your plecos breed. some are cavespawners so is easier to recreate, others spawn in mudbanks, so basically you need a bond with a lot of mud/silt