hi all, i was just wondering... i took my internal filter out of my Rio 180 and am now using an external filter... now i have been told that the thing inside the actual filter is a powerhead?? is this right? well if it is... could i put the powerhead in my tank to improve filtration, to sweep over the sand and help move the rubbish towards the sucker end of the filter (the intake bit). im just trying to think of ways to help fight agaisnt algae... thanks for looking.