+1 to @Tim'sReef above:RO water I’m still not sure what the DI bit means. 0tds from a big gas bottle looking tank that I attach to a hose
RO means "Reverse Osmosis" which removes a significant portion of TDS "Total Dissolved Solids" from the water but does not always drop TDS to zero.
DI meands "De-Ionization" which is an additional step usually using resin beads to remove more TDS.
RO alone that puts out 0 TDS water has no need for the DI stage, but most people need RO/DI systems (both) in order for 0 TDS output water.
True 0 TDS water is practically pure H2O, so it does not matter for practical purposes how the water was purified as long as it was.