Canister Pressure Dropping

[Nelson]

I've observed that my large EHEIM return pressure is not what it used to be.  I maintain it regularly as well as the hoses.  If it makes any difference the filter is at the same level as the tank.  Any ideas on what could be causing the problem??

[Evan]

Could it be sucking air somewhere.  I have noticed after the pipes are a part a few times the seal is not what it used to be on mine.

Also by maintenance do you mean changing the filter floss  (Just the top layer)   and cleaniong the instake valves?

I would also chack the impellor so see if it looks ok.

[Nelson]

Could it be sucking air somewhere.  I have noticed after the pipes are a part a few times the seal is not what it used to be on mine.

Also by maintenance do you mean changing the filter floss  (Just the top layer)   and cleaniong the instake valves?

I would also chack the impellor so see if it looks ok.

Thanks, all good suggestions.  Yes I clean filter pads religiously and replace pads as required.  The impeller is cleaned regularly so I can rule that out.  I'm a bit of a water quality freak so I pay a lot of attention (obsessed?) to all my filters.  I would think that if a hose connection or the like is sucking air it would leak when I turn the filter off, but I have no leaks.  Mystery continues....

[BigDaddy]

One thing about plumbing I learned from working on pools is the suction side of a pump is always the one to watch for leaks.

When the pump is off, there is no pressure, so the cracks are essentially water tight; no water drips out.  However when the pump is ON, the cracks are not air tight, so air can be drawn in.