The Eheim valves are about $75 for the intake hose & $35 for the output hose. The valves make servicing the filter extremely easy. You could always make your own using PVC, someone on this site has made their own, I just don't remember who it was.
What does the media look like in the bag? The only mechanical media I saw in the video was the pad. I don't think you have enough media in the filter to perform proper mechanical filtration.
How often are you cleaning the filter? How dirty is it when you do clean it?
