Using bottled distilled water instead of RO/DI

If you are getting 0 on the TDS meter than I would say you have good water. I used to go this route, but having my own RO/DI was the best reefing purchase I have made.

 

Most vending machines are RO only or RO followed by ultraviloet light and I have never ever seen one produce 0 TDS. An RO membrane is a 90 to 98% efficient device and cannot remove everything, its not possible.
I would check the calibration of your TDS meter using a 442 solution and distilled or know 0 TDS RO/DI. Meters must be kept clean and capped when not in use. Every time I use my handheld TDS meter (COM-100) I triple rinse it in DI after each use and before i put it away to keep it clean and accurate. I also use a squeaky clean clear glass drinking water glass which has been washed by hand in real hot water so it has no dishwasher soap residue or hard water spots. The glass is also triple rinsed with RO/DI then put away upside down to keep dust and salt spray out.

 

ill take a pic of it next time i go..it does rodi, some other filters, and ultraviolet light...its called glacier and its a green maching with leds and touchscreen display and stuff, its a nice machine, and its huge..it 100% is rodi.. all total it goes through like 8 different types of filtration.. most winn dixie grocery stores have them outside...if this machine didnt do rodi then i would have bought an rodi unit..but with my 40 gallon its no point in me having one..i could hit a driver to the machine from my house so it only takes a few seconds to get to it if i ever needed an emergency bucket.. and yeah man i take care of all my meters and stuff too like u, trust me this machine has legit water at a great price.. i dont even let people put their hands in my tank to point out something they want, im def not gonna be using bad water..

 

I have never seen a RO/DI vending machine anywhere in the Southwest and I do water for a living. Thats cool!