Deer Park TDS = 2
I was lending a TDS Meter I had to a friend at work and I was showing him how to use it with the Deer Park water cooler we have. I was impressed to see 2 TDS.
Like Tap water, spring water can be used as a last resource. Sometimes when I really need to top off and have nothing around, I'll grab a bottle of Poland Spring :shhh:
When it comes down to it you can use any water that you want to but the problem is that you don't know what kind of undesirables that you have in that water. Even a TDS meter doesn't tell the whole story. High TDS water that has little or no heavy metals, phosphates, nitrates, silicates, etc. could be better than the very low or zero TDS water that has high levels of phosphates and silicates. Best to strip it down to almost nothing with an RO/DI and let the salt mix replenish all of the necessary elements and minerals rather than take the chance IMO. In a pinch use distilled water.