Total Dissolved Solids (TDS)

I've a Doulton Ultracarb counter top filters - 2 candles.  I did a TDS test on a cup of filter water and it has TDS value of 260. This result is much higher compared to a bottle of Dasani which is only 50. I wonder what the average TDS level is for the Doulton filtered water? How can I reduce TDS level in my Douton filtered water?

 Because TDS consists mostly of dissolved minerals and salts in the water, you will not see a drastic reduction in TDS, nor should it be an accurate measure of water quality. Our filters leave essential minerals in tact, while technologies such as Reverse Osmosis (Dasani) and Distillation strip them from the water making a very acidic/aggressive water.