RODI, TDS Reading
- Thread starter CooperS
- Start date
firerock
New member
Hum, that's pretty bad reading for your final h2o out of the rodi system. I always aim for the reading to be under 3 ppm or less. Most of times, I get about 0-1 ppm. And my normal water is about 190-230 tds.
My godmother's house drinking water is 45 ppm, and that's just 3 stages ro. With DI, you should get a lot better reading from your water than 29ppm.
My godmother's house drinking water is 45 ppm, and that's just 3 stages ro. With DI, you should get a lot better reading from your water than 29ppm.
golfish
Team RC
What kind of RO\DI unit is it and how many GPD?
I get zero to 1 off my RO and zero off the DI but these hand held TDS meters are not all that accurate. I would think anything less then 5-10 off the RO is good and anything less then 2 off the DI..I stopped testing the TDS off my DI when I got the PO4 colorimeter. I just keep an eye on the PO4's off the DI, when I see them start to rise I swap out the resin.
FWIW, I run two DI's off my RO.
I get zero to 1 off my RO and zero off the DI but these hand held TDS meters are not all that accurate. I would think anything less then 5-10 off the RO is good and anything less then 2 off the DI..I stopped testing the TDS off my DI when I got the PO4 colorimeter. I just keep an eye on the PO4's off the DI, when I see them start to rise I swap out the resin.
FWIW, I run two DI's off my RO.
golfish
Team RC
I don't know about you but every single PO4 test kit I've used gives me a zero reading. After using Steve's colorimeter last year I felt I had to get one (thank's Steve) I bought my Hannah meter from Madison, seeing how he's not around anymore you might try Custom Aquatics. I saw this link a few weeks ago. It looks like a better deal then the Hannah meter.
http://www.milwaukeemeter.com/index.html?lang=en-us&target=d27.html
Unresistible Blue
New member
Re: RODI, TDS Reading
There is something wrong with your system or your meter, or you it is time for some replacements.
1. Is your meter calibrated?
2. 310 for tap water is nothing unusual.
3. tell us what the tds reading is after the RO (before the DI)
29 after the DI tells you your DI resin is spent and needs to be replaced. Before you replace it though let's make sure your membrane is working as it should. Need an answer re the post RO (pre DI) tds.
4. What is the gpd rating on your membrane? Membrane brand name?
<a href=showthread.php?s=&postid=7036744#post7036744 target=_blank>Originally posted</a> by CooperS
Hello,
I have an RODI filteration system. The filter is about 6 month old.
I just bought an Dual TDS meter today and my measurement are 310 ppm on the inlet and 29 ppm on the outlet.
Is that exceptable?
Thank you,
Bert
There is something wrong with your system or your meter, or you it is time for some replacements.
1. Is your meter calibrated?
2. 310 for tap water is nothing unusual.
3. tell us what the tds reading is after the RO (before the DI)
29 after the DI tells you your DI resin is spent and needs to be replaced. Before you replace it though let's make sure your membrane is working as it should. Need an answer re the post RO (pre DI) tds.
4. What is the gpd rating on your membrane? Membrane brand name?
ReefLife1680
New member
I think it might be time for a RO unit complete filter change. Filsters may have been exhausted?
Unresistible Blue
New member
Well... filters don't really become "exhausted."
Sediment filter fill with sediment and start to chock of water supply to the rest of the system.
Carbon blocks clog the same way, and additionally, the activated carbon loses its effectiveness (I guess you could call this becoming exhausted).
RO membranes can become damaged, or chocked with mineral deposits ("scale").
DI resins exhaust, and become ineffective ofver time in binding with ions.
Remember that sediment and carbon prefilters don't do anything to reduce tds - they just protect the membrane.
Sediment filter fill with sediment and start to chock of water supply to the rest of the system.
Carbon blocks clog the same way, and additionally, the activated carbon loses its effectiveness (I guess you could call this becoming exhausted).
RO membranes can become damaged, or chocked with mineral deposits ("scale").
DI resins exhaust, and become ineffective ofver time in binding with ions.
Remember that sediment and carbon prefilters don't do anything to reduce tds - they just protect the membrane.
Hello,
This is what I have. (6 month old)
http://www.airwaterice.com/product/1DUALHR.
And I have the dual TDS meter got from Marine Depot.
Packageing said its Factory Calibratedââ"šÂ¬Ã¢â‚¬ÂRecalibration is not necessary.
I can't really measure the RO line, because my meter is an inline type. I'm ordering the filter replacement now.
Thank you
This is what I have. (6 month old)
http://www.airwaterice.com/product/1DUALHR.
And I have the dual TDS meter got from Marine Depot.
Packageing said its Factory Calibratedââ"šÂ¬Ã¢â‚¬ÂRecalibration is not necessary.
I can't really measure the RO line, because my meter is an inline type. I'm ordering the filter replacement now.
Thank you
mikeo1210
Premium Member
Are you flushing the membrane each time you make water? If not this will wear out your DI in short order.
The first system I bought from AWI didn't come with the "fast flush" but it's a simple add-on. You can make one yourself our get one from them: http://www.airwaterice.com/product/FF.
The first system I bought from AWI didn't come with the "fast flush" but it's a simple add-on. You can make one yourself our get one from them: http://www.airwaterice.com/product/FF.
