Do rusts get trapped or passed thru sediment filter when it's so dirty?

Question

There is something so confusing. Some web sites mentioned when the sediment filter is very dirty. It can make water harder to pass through. Some mention as the sediment filter traps more dirt, rust, it becomes more effective filter.

On the other hand. I read some web sites mention that when sediment filter is full or so dirty, the rust and dirt can pass through them and get into your faucet, etc.

What is the truth of it? I'm referring to sediment filter where the water is pushed from outside wall to the inside like the following illustration. How does it exactly filter when it is already so dirty? Does it just lessen water or make rusts pass through it? How?

Answer 1

when the sediment filter is very dirty. It can make water harder to pass through

This is TRUE- when the media is clogged, it takes water longer to pass through, so I guess an alternate way to express that would be that it is "harder" for water to pass through.

as the sediment filter traps more dirt, rust, it becomes more effective filter

This is also TRUE- think of it as you would en engine's air cleaner, as the filter media becomes contaminated with particulates, the spaces where the fluid can flow through (fluid... like air or water) can become fewer and smaller, restricting flow but also trapping proportionally smaller particulates.

when sediment filter is full or so dirty, the rust and dirt can pass through them and get into your faucet

This might be true depending on the filter design. Most simple home sediment filters will just continue to exhibit decreasing flow per unit of time until the performance is so unacceptable that the user takes some action. I guess there could finally come a point when the differential pressure across the media is so high that particulates previously trapped are forced downstream... not sure.