Walmart distilled water used to be $0.98 per gallon. Now it is $1.48/gallon. Looking at possibly getting a water distiller. Amaon has some in the $100 range. You still have to buy over 60gal at that price to pay for the distiller. Another problem is the quality of the distilled water. Once I got and ALMOST used the Walmart Parents Choice Distilled Water in the battery. You have to do some deep checking, but they actutally ADD MINERALS to Parents Choice Distilled water! Now I can't be sure if distilled water is really distilled (i.e. 0 minerals) or if it has minerals added. To add to confusion, the distillers advertise <2ppm dissolved solids. So they don't really make 100% TDS free distilled water either. Any ideas? What do you do? Prices going up so much and trust of what you are getting is making me look for options. I suppose no slids is best, but is there any amount of TDS that is ok in a lead acid battery? 60 gal is a lot of water to use, but 1 gallon of the wrong water can ruin your day.