The CSV125 needs clean water and is not designed for dirt or iron. Even so some installers still install the CSV125 with iron and/or dirt. When the CSV125 becomes clogged with iron, they just say CSV's are bad instead of figuring out they just used the wrong CSV for the job. Some even install a CSV in an application they know is not good, that way they can say "see I told you those CSV's are no good". Some just don't want to learn anything new. Other just don't want you to have something that saves you so much money, as that takes money out of their pocket.
We make several different CSV's for this reason as well as others. The CSV1A is designed to handle dirt and iron. Iron and dirt doesn't hurt the CSV1A anymore than it will hurt the pump, check valve, pressure switch nipple, etc. And if the CSV1A becomes clogged with iron like a check valve does, it can easily be taken apart and cleaned.
There are also ways of cleaning up the iron in the well so the pump, check valve, CSV. etc., doesn't have to deal with it at all. I have had many customers who tell me the Sulfur Eliminator works very well for this.