Help with mystery pond pump problem

[ashtons99]

I’ve got a Laguna pond pump, it’s about 18months old. The pump feeds a pressure barrel filter then a EA easy pod and back into the pond.
This last week the flow has been reducing to a dribble. I found if I turned the pump off and back on again the flow is restored but after a couple of hours it starts to slow again.

The previous Laguna pump lasted me 18yrs !

I’ve checked the filters and they are all clear.

I’ve had the pump apart and cleaned the parts that can be cleaned.

I’m at the point where I’m presumimg the pump is slowing for some reason. I’m on the point of buying another pump but wondered if anyone can offer any possible solutions before I do

 

[blup]

Possibly a pressure/flow related switch in the pump?

 

[ashtons99]

It’s looking like a partial blockage in the pipe from the pump to the filter.