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RODI from LFS - TDS Readings too high? - Should I use?


RemoGaggi

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I don't have a RODI unit and may get one in the future.  I've been using distilled water for my water changes, but I recently got some RODI water from 2 different LFS to try out.  Using my cheapo TDS meter, I got readings of 22 and 40 from the 2 different stores.  I ended up not using either, but wanted to know what you all think.  Are these readings too high to use.  Should I just use this water for rinsing out things instead of going in the tank?  Thanks.

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1 hour ago, RemoGaggi said:

I don't have a RODI unit and may get one in the future.  I've been using distilled water for my water changes, but I recently got some RODI water from 2 different LFS to try out.  Using my cheapo TDS meter, I got readings of 22 and 40 from the 2 different stores.  I ended up not using either, but wanted to know what you all think.  Are these readings too high to use.  Should I just use this water for rinsing out things instead of going in the tank?  Thanks.

22 and 40 are way high. My RO is lower than that before the DI stage. I wouldn’t use it. 

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1 hour ago, RemoGaggi said:

I don't have a RODI unit and may get one in the future.  I've been using distilled water for my water changes, but I recently got some RODI water from 2 different LFS to try out.  Using my cheapo TDS meter, I got readings of 22 and 40 from the 2 different stores.  I ended up not using either, but wanted to know what you all think.  Are these readings too high to use.  Should I just use this water for rinsing out things instead of going in the tank?  Thanks.

Yeah, my tapwater comes out of the tap at 30-40...those numbers are too high, I wouldn’t use without investigating further.

 

Could be a few things going on:

  • your LFS may not be changing out their filters often enough so the water isn’t properly filtered
  • the LFSs may make their RODI in the same container as their saltwater so there may be a little saltwater left in the container that causes the numbers to be high even though the RODI was filtered properly (that’s the issue with one of my LFSs)
  • your containers could have been dirty, or could be leaching something into the water
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Meh, you could use the 22ppm RO until you get you your own RODI. It's hard to say it's terrible without knowing what the 22ppm TDS is.

 

If the tank is small then I would also go with distilled for the time being cause why not.

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Both LFS’s probably have spent ro membranes and haven’t changed di resin in awhile. based on those numbers the membrane is probably only performing at ~60% efficiency and even if they are replacing the DI resin regularly the resin is getting spent quickly that’s if they are even using DI resin. I had an LFS that was just selling RO water and the numbers were pretty similar.  

 

Unfortunately this is the case with a lot of LFS. When I bought water from the LFS I always asked them to test it, the ones that refused usually had poor water. There are a few in my area that keep up on maintaining their water filters and will do a TDS test before selling it to you when asked. 

 

If your in this for the long long term your own RO/DI is a relatively inexpensive option to have your own water on demand. We have terrible water here so mine is set up as dual purpose, provides DI water for the tank and also drinking water for the house. What we spent on bottled water in a year paid for it. And now we’re not throwing away hundreds of plastic bottles anymore. 

 

However if you have a small small tank I would just use distilled water or maybe look into a home distiller 

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as sancho states, my RO before DI is way lower then that.

The LFS is obviously skimping out on maintenance, and doesn't know the filters need replacing, or just doesn't want to pay the cost end. 

 

Kindly let them know the filters need replacing, and also the DI resin is worn out.

Kindly let them know they are not selling DI grade water with a TDS that high. 

 

If they dont change the filters, i would not do business with them ever, because if they are skimping out on something simple as replacing filters, it makes me worried what else they are skimping out on, like QT. 

 

@Sancho home distillers are terribly inefficient, and make a hugh mess. 

You will eat most of any savings via electricity bill, and scrubbing the distiller of deposits will make you probably scream. 

You would at least still want to RO the water first, before you distilled, which defeats the point as if you have an RO, all you need is to add the DI option to finish it.  

 

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  • 4 years later...
IJustNeed1MoreCoral
On 3/3/2019 at 1:36 PM, Naekuh said:

as sancho states, my RO before DI is way lower then that.

The LFS is obviously skimping out on maintenance, and doesn't know the filters need replacing, or just doesn't want to pay the cost end. 

 

Kindly let them know the filters need replacing, and also the DI resin is worn out.

Kindly let them know they are not selling DI grade water with a TDS that high. 

 

If they dont change the filters, i would not do business with them ever, because if they are skimping out on something simple as replacing filters, it makes me worried what else they are skimping out on, like QT. 

 

@Sancho home distillers are terribly inefficient, and make a hugh mess. 

You will eat most of any savings via electricity bill, and scrubbing the distiller of deposits will make you probably scream. 

You would at least still want to RO the water first, before you distilled, which defeats the point as if you have an RO, all you need is to add the DI option to finish it.  

 

My lfs is selling their RODI at 0.98 TDS ..My own RO water that I have reads 0.14...

Would My RO water be better ?...serious question..I'm on the hunt for a lfs that has a lower TDS untill I purchase a RODI system... 

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