A TDS Mystery (RODI System)

[bsfmaximus]

Around last thanksgiving I purchased and installed an RODI system. I also purchased a TDS EZ meter via Amazon for $10-15. My tap water sits around 150 and my filtered water ended up being 0 for a while. I tested periodically and after a few months my TDS seemed to be going up into the single digits then around 15 by month four. Things came up and I put off buying/installing new filters right away. I tested again around months five and six and my TDS was back down in the single digit range. Now after 9 or 10 months of the same filters, my TDS is still only around 5. I was convinced my TDS meter was broken, so when I came across a deal on another one, I bought it. Sure enough it is also testing my water at 5 ppm TDS.
Has anyone else experienced this - TDS goes up as expected then goes and stays down? Is there something I don't know about and should I change my filters anyway even though my level seems good?

 

[The Rook]

Filters and di are really reasonable thru Bulk Reef Supply. I like mine at zero so i change mine as soon as it starts to creep up a couple points.

 

[twilliard]

@AZDesertRat
Depending on how your DI is packed it may have been stirred and at the point you may see different readings.

 

[Buckeye Hydro]

Be aware that the uber low end TDS-EZ meter you bought does not have ATC - automatic temperature compensation. On our website you'll see in the description of the TDS-EZ "Not recommended for applications requiring readings near 0 ppm (e.g., deionized water)."

This really isn't a meter well suited to what you're using it for. At a minimum, move up one notch to the TDS3.

Russ

 

[aquaman67]

How are you testing your water? Are you using a glass or plastic container?

Plastic cups can give you funky readings.

Even with glass make sure there is no residue from soap, etc.