What is it?

[PNW]

When I empty my bag filter I find a dark gray material in the bag with the consistency of pumice. I also find it in the bottom of my toilet tanks. You can't see it in the water either. It seems to go through the 1 micron filter I am using. This all started when a test of my well was conducted 1 year ago. What is it?

[Alex]

I have not specifically heard of any grey sediment before so I am not sure exactly what it is. You should be able to remove any sediments with a sediment filter.

The smallest thing that can be seen with the naked eye is about 10 microns. So the 1 micron sediment filter should be removing these sediments.

Is the particles gelatinous or solid particles?

Anyone else that has heard of this, please chime in! I'm curious myself.

[PNW]

The stuff is like pumice. It has a gritty feel when rubbed between the fingers. The filter is right after the pressure tank so it it can't come from anything else down stream.