Need help with RODI unit … what's wrong??

[arch85]

Hey guys,

I have a 5 stage unit.

1st: 5 micron filter
2nd: 1 micron filter
3rd: Carbon
4th: dual 90 gpd membranes
5th: DI

The above are in the order in which water goes in.

I measured the TDS out of the DI and it was around 9-10. I measured the TDS out of the membranes and it was 0.

Please note that ALL the cartridges are new.

Can you offer any insight on what might be going boom?

Thanks!

 

[ritter6788]

Did you run a few gallons through the unit before checking the TDS?

 

[skinz78]

New DI needs to flush for a few gallons.

 

[arch85]

Sorry, I should have mentioned, they have already made about 200 gallons, and still showing the tds..

Sent from my SCH-I535 using Tapatalk 2

 

[ritter6788]

Is it an inline meter or a handheld?

 

[arch85]

It's an inline meter but not hooked up; so I am using it as handheld..

Sent from my SCH-I535 using Tapatalk 2

 

[skinz78]

I think I would start over with new DI resin.

 

[arch85]

I think I would start over with new DI resin.

But it was a brand new cartridge with all new resin … you still it's exhausted after merely 200 gal or so of water? :-/ ...

 

[AZDesertRat]

You cannot use an inlne meter as a portable, the probes must have flow past the elements to register with the least bit of accuracy. You can't just stick them in a glass of water, this is one of the biggest drawbacks of inline meters.
I suspect your DI resin is exhausted. Find yourself a handheld TDS meter to confirm the readings or go ahead and install the IN tee and probe after the RO and the OUT tee and probe after the DI and receheck the readings. Make sure the probes are installed all the way in the tees and that they are rotated in the correct orientation, this is important also. You can swap probes temporarily to see if they agree or if the readings follow the probes in which case the meter may be bad or out of calibration.

I would also temporarily install one of the tees and probes in the tap water line to check your tap TDS so you can calculate the rejection rate using the tap and the RO only TDS numbers.

What is your water temperature, water pressure at the membrane and your exact measured waste ratio? These all have a bearing on system efficiency and DI resin life.

 

[arch85]

You cannot use an inlne meter as a portable, the probes must have flow past the elements to register with the least bit of accuracy. You can't just stick them in a glass of water, this is one of the biggest drawbacks of inline meters.
I suspect your DI resin is exhausted. Find yourself a handheld TDS meter to confirm the readings or go ahead and install the IN tee and probe after the RO and the OUT tee and probe after the DI and receheck the readings. Make sure the probes are installed all the way in the tees and that they are rotated in the correct orientation, this is important also. You can swap probes temporarily to see if they agree or if the readings follow the probes in which case the meter may be bad or out of calibration.

I would also temporarily install one of the tees and probes in the tap water line to check your tap TDS so you can calculate the rejection rate using the tap and the RO only TDS numbers.

What is your water temperature, water pressure at the membrane and your exact measured waste ratio? These all have a bearing on system efficiency and DI resin life.

Thanks guys -- I checked again, and seems like TDS is around 0-1PPM when I hold the inline TDS so that there's proper flow through the probe. So I guess all is well. I have ordered a hand-held TDS regardless for a more accurate reading down the line.

Thanks for all the help, appreciate it.