sorry to discuss this in your thread Taggerz (hope it's OK). But TDS and hard water are two different things. Water is considered hard when it has a relatively high concentration of calcium and magnesium ions, this is only 2 out of the 3 things that make TDS. Water softeners do not reduce TDS. They remove magnesium and calcium ions, which cause hard water, but these ions are replaced with an equal number of sodium or potassium ions. This leaves overall TDS unchanged.
Ferts are also going to increase the amount of TDS in the water.
I understand what your saying, but i'm unsure whether it has anything to do with what water you're using. I do know that mini landscape rock increases hardness and will to a point increase TDS, but not a great deal.
