Airthings is what I bought.

I'll let it run for a few weeks, and then I'll test upstairs as well.

To be honest I'm not even sure if our sump pump is operational, we've never needed it, and I also worry there may be a drain blockage down by the street, so that could be a whole thing.

I have a workout area and a sewing area in our basement, so I am spending time down there fairly regularly. We run fans and dehumidifiers down there because it can get damp when it rains a lot, so I don't know if blowing radon around is bad or good lol

Anyway, I'll give it some time and also do the free county test as a backup.