tested the blue camco filter with a TDS meter

Actually one and the same bottle of water might differently affect stomachs of different people. Last year my husband brought home one strange thing. I don't know how to name it, but we used it to check the quality of water. We took bottled water, water from filter and tap water. We expected tap water to be the worst one, but in reality it was a little better than bottled one. Water from filter (we had Berkey filter) was the best one. Probably the result might had been better, if we had taken bottle from another company, but who knows.
Anyway even today we still prefer to drink filtered water, and stay away from experimentations.