I have used my Love Water  Distiller to make 50 Gallons of distilled water
in the last month.
What I found is it works best if you do not put the full gallon of water in
it.
I fill about 8 ounces shy of Gallon I test each batch it comes out, it reads
0  on my TDS meter.
I clean the Distiller every 10 Gallons or so (depends on your water).
If you let it get too dirty you may get water that reads 1 on the TDS meter.
I also use hot water from faucet to speed process as my hot water heater is
by natural gas which is
cheaper than Electricity. I needed the Distiller because of the Quantities
of Distilled Water I use.
I use water injection in my twin Boat Engines which saves me 25% on fuel. 
I have had no problems with this Distilled Water in making my CS.
I have had Distilled Water from store that ran 1 to 3 on my TDS meter.
Based on cost of Electricity I figure it costs me less than 35 cents per
Gallon of Distilled water
Not to mention having your own source and less to lug from store.
 
 
 
  Bob