Might be confusing TDS and conductivity? I chose to monitor conductivity cause the guy who was helping me with the water situation had taken water samples from down where rays are caught - his measurements were in Microsiemmens so could relate better IF I was giving him readings in the same measurement.
Only TDS readings I take are water going into and out of my RO. Although I do believe I saw a TDS pen amongst some other stuff I got with a tank deal, maybe it would be easier for me to go measure my systems in TDS rather then hoping for someone with conductivity numbers to share.......