There is a lot of algae settled on the bottom of my pool. I bought this filter/pump system and hooked up a hose and vacuum brush to it. I ran it for about 3 minutes and got a low flow warning and now suction is way low. Of course, Intex' customer service dept. has no one that really knows what is going on (or speaks English) and there are no directions on how to clear the pump up. Any suggestions? Backwash? Other ideas? Your help would be greatly appreciated.