Well water comes out red

In a well water with no oxygen (anoxic) and which has has a high iron content, the iron is soluble and in solution, but once it is pumped from the ground and exposed to oxygen in the atmosphere, soluble iron chemically reacts with oxygen and insoluble iron oxide forms (“rust”) - the iron oxide then precipitates from solution - this is the red particles you are seeing. You’ll need to filter the iron particles out with an appropriate filtration system if you are using it in household.

Can consider aeration as well but need appropriate PH levels. More cost upfront but less cost/maint over time.

Would still recommend a filter but it would last considerably longer.

It could either be iron, as Craw said, or drilling mud if you are in an area with clay.

We drilled a well in December of 2021 for a new construction. Didn't put a filter on it initially. In October of 2023, we started noticing sediment and a red tint to the water in the house. It wound up being drilling mud. We put a pH correcting and sediment filter on the well, flushed it out, and haven't had the issue since. The driller indicated to me that he had gotten several calls on newly drilled wells that hadn't stabilized over time because of the drought's effect on the water table. I have no idea if that's accurate, but it made sense to me the way he explained it.

Regardless, the appropriate filter should solve your problem.

I sent a water well sample to LSU (school of Ag, I think) and got a complete analysis mailed back to me. It wasn't very expensive. Call the university.

We had a company come and do a full water test, it was like 300-500 if I remember. Told us exactly what was in the water, set the house up on a full bladder and filtration system.

ETA: we have lots of iron in our water, you can smell it (before the filter that is)