[Adam]

Do you notice any small bubbles coming out of the output? If so it might be drawing air at some point in the plumbing.

Or it may be turbulence... I did an closed loop pump istallation on a clients tank with a mag 18 that was sitting above the tank running two sea-swirls, and because of the bends I had to put into to get the plumbing of the intake the way the client wanted it unless you throttled the pump back about 25% it would make a churning type sound. The only thing I could chalk it up to was that the bends in the plumbing were causing turbulence in the incoming water that threw the impeller out of balance and caused the rattling.

The later would be my guess based on all the angles you have in the plumbing. Try straightening some of the angles, using 45 degree angles or use CVT to make the angles more gradual and see if that doesnt fix it. I would be very suprised if the noise was application based and not a manufactuerer defect.

 

[Adam]

Could you post pics of it in an exploded view type thing? How are you sealing the top? Are these all pieces that could be easily obtained from a local hardware store?

 

[Adam]

What about connecting the pump directly to the canister via the threaded union? That would elimiate one 90 degree bend, and give you more room to play with on the right side where it returns water to the tank.

The other thing I just thought of, is that the canister might be causing too much resistance. Is there a way to test the filter with no media in side it? That would tell you if its a restriction issue or whether its a plumbing issue.

 

[Adam]

I would try to get a replacement... the pump shouldnt have broken at normal hand tightening pressures unless your He-Man. I have had problems with structural flaws in bulkhead fittings similar to what it sounds like your describing. It doesnt hurt to check because if you could thread the union directly to the pump you would be able to solve alot of your space issues.

 

[Adam]

I'm not having much luck finding anything except industrial expandable pipe caps online. What hardware store did you pick yours up from, and where would I look when I went in?