tested the blue camco filter with a TDS meter

I have used my RV for hundreds and hundreds of nights over close to 10 years. I have never filtered the water. Only once did I encounter a problem. The water was cloudy and I did not use it. I think it had been tested and was safe but I did not want the silt in the tank and lines. I guess a filter would have been useful for that situation, but I think avoiding the water entirely was a better choice.

You can spend a lot of money on water filtration devices. Some of them even remove chlorine, which is a really bad idea. Instead I just use a Brita for filtering drinking water.