One day we turned on the tap in the wet kitchen, which runs from the water mains, and were quite disgusted at the colour. I realised that the external water filter hadn't been changed since the previous owner moved out over a year ago, and a lot of water had since passed thru it during the construction process etc. I had totally forgotten about the external filter because it was overgrown by a huge bush in front of the house, which by the way also needs some urgent trimming.
We went out and bought a whole new unit, not even gonna bother to replace the old filter element. Those things are cheap these days anyway. Check out the old filter. It's like a cess pool in there. Totally, absolutely disgusting.
An elbow pipe. This is after the filter in the line. Also fully disgusting inside. Decided to buy a new elbow too.
I had to cut a path thru the bush to get to the filter, which was installed over the drain. It really stank in there, decaying organic matter and all. But in the end, WIN for the plumber.