TDS Meter

[PufferDad]

I have a 3 stage RO unit that I want to test for TDS for my reef tank. What experience do you have with your TDS meters? Which one to buy? How often to use?

[Samper]

I have tds and ec meters in a few different brands. I usually talk airwaterandice.com into giving me one with each filter purchase. I prefer the tds meters just because there are no conversions to do or anything you just read it. There are options available in these. Some hook up inline with the filters before and after giving you an idea how your RO is performing at any given time. There are others that are portable and you just fill the lid with a sample of water to test dipping the meter into that. Either way they are valuable tools for us. I test once a week and change sediment and carbon cartridges as soon as I register anything other than 0 tds from the filter. The DI resin I change less often than the other two.

[charlie]

This is what I have been using for the past year.

HM Digital In-line Dual TDS Meter (Saltwater Aquarium Supplies > Reverse Osmosis > Purity Monitors )

I check every time I turn the unit on.

[Samper]

I think that I have every single tds meter that airwaterice.com offers and a few of the ec meters that they now don't seem to have. I haven't had a problem with any of them.

[charlie]

Since we posted at about the same time, I'll say that I don't change my filters until I read 3 on the "in" line from the RO membrane. My output is usually at 1-2 from the DI, any higher and I change the DI cartridges.