I just set up my new Pro Clear Aqua 125 w/d filter today. The last thing that I could not get the new filter to run is to siphon the U-Tube. I have tried to insert an air-tube half way through the U-Tube and tried to suck the air to siphon. But this technique is not working...how do you guys siphon yours. I have an E-shop prefilter box for my w/d filter. Are there any other tricks that you guy do to siphon. I need help...please help...