Exactly, a lot of stuff geared towards this hobby is pure fluff and waaay overpriced. IMO if it reads 0 in bottled water, it works good enough to judge when to change my filters. Mine gets used every 6 months or so, when the season changes. I tested mine a month ago, 2ppm, change out media, double check with the wifes bottled water, reads 0ppm. End of story, back in the drawer till march or so.

If the meter is out the other direction it won't say -10ppm in the bottled water, but it will still test your RO water at -10ppm of whatever it is, so your RO water could be 9ppm and the meter will still read 0ppm. That's one of the reasons why you need to use calibration fluid not distilled water.

Of these meters that you can't calibrate, I would like to see what they read when someone puts them into 342ppm calibration solution just to see how far off they really are. I just don't see the purpose of using something to test when the tester itself isn't accurate. That makes no sense at all to me. :lol:

To each there own. I bought this years ago on Kevin at RCs recommendation to save a few bucks. But I will say, these are quite simple, Its a simple measure of conductivity, that's it. I highly doubt a bottle of distilled water or new filters and media will read 10ppm, in fact if it did, I'd just use that as my baseline instead of 0, its not a ph probe. Just offering something up that costs a lil less is all.

Then don't use it ;) I personally couldnt care if it read 342 at 342. As long it reads a difference between 0 and something, something is too much and ill change the filters. If it said on/off, yes/no, crap in your water/water is clean, that would be good enough

I guess it is to each their own. I find more value in my TDS meter than my pH meter. :lol: I understand there are lots of cheap meters out there, I have one already. I'm looking for a reasonably priced meter with a specific option - that being automatic or push button calibration instead of screwdriver calibration. Thanks for offering up your suggestions though. All suggestions are always appreciated.

Hey Myka,

I have a HM Digital dual meter on my RO system. You can't calibrate, and I never thought about it. But now I am wondering what it really is, so at least I know. What calibration liquid would you recommend?

I just changed my filters 2-3 weeks ago, and it is reading 0ppm, but as you stated, is it really that. You got me curious. As my filters are new, I am not worried, just curious.

I use the HM Digital 342 ppm sodium chloride solution. Any brand will work, but I find the 342 ppm to be the most suitable for our use. You want to pick something close to the ppm you will be testing.