I've had a Prowler 930w for a few months now and I am very disappointed. it doesn't have sufficient suction to clean the corners where the angled walls meet the floor on the deep end. I run it for 2 2 hour cycles and there's a lot of dirt left behind. this is with the pleated filter and hosing it down between cycles. Is there anything I can do? I had a zodiac mx-8 and that cleaned much better in a couple of hours.