RODI Mistakes/Idiot needs help

[NitrateKillah]

The replacement filter and membrane are working great, but the old connections were brittle and showing cracks, so I decided to change them.

Since replacing the plumbing connections, my RODI water is reading over 30 ppm, even though the membrane and filter are only a few days old. I must have made a mistake with the plumbing lines.

Could you please help me troubleshoot what I did wrong? If possible, please explain it in very simple, step-by-step terms so I can easily follow along. My TDS meter is now reading 777.

 

[UncommonSense]

So, it appears that this system has the correct tubes in the correct places… a few preliminary questions would be:

— did you check TDS after changing your membrane, and before changing all these fittings? — I suspect the fittings could be a red herring!

— what does that pressure gauge read when the system is producing water?

— are the TDS probes aligned to have their two metal tips perpendicular to the flow of water past them? (They can give false readings if tips are oriented to be parallel with water flow)

 

[NitrateKillah]

So, it appears that this system has the correct tubes in the correct places… a few preliminary questions would be:

— did you check TDS after changing your membrane, and before changing all these fittings? — I suspect the fittings could be a red herring!

— what does that pressure gauge read when the system is producing water?

— are the TDS probes aligned to have their two metal tips perpendicular to the flow of water past them? (They can give false readings if tips are oriented to be parallel with water flow)

Gauge is around 90, it was 100 before fitting change. Not sure what you mean by perpendicular, I try to follow exactly what I saw originally.

The TDS was working fine before changing out fittings. Google says 777 means I am by passing the filters??? I am reading that the auto shut off valve can get stuck? You think this is the issue? the fittings had a lot of calcium build up when replacing them.

 

[Freenow54]

He means the 2 probes are side by side getting the same flow at the same time in the tube not one in front of the other

 

[NitrateKillah]

He means the 2 probes are side by side getting the same flow at the same time in the tube not one in front of the other

I see, I will try again.

 

[UncommonSense]

Gauge is around 90, it was 100 before fitting change

Wow, that’s some extreme home water pressure! Honestly, you might want to put a pressure regulator before this RODI, or have a plumber see if you have a home pressure regulator which can be adjusted… the RODI housings, fittings, and tubing are typically only rated for around 85-90PSI (and your housings look to have some UV damage which inevitably makes them weaker!)

The TDS was working fine before changing out fittings. Google says 777 means I am by passing the filters

If RO product water TDS was low (good) with the new RO membrane, before fitting swap, then water isn’t channeling around any RO membrane seals!

I am reading that the auto shut off valve can get stuck? You think this is the issue?

I doubt it, I’ve gone through 3 auto shutoff valves in 11 years or so… they would either fail closed and provide little to no water to the system, or fail open and dump water out the waste line 24/7 if the system is pressurized while idle (all 3 of my ASO valves failed open)… this wouldn’t affect product water TDS!

the fittings had a lot of calcium build up when replacing them.

You’ve got plenty of water pressure, and had low product water TDS with the new membrane… The only thing I can think of is this calcium in the lines… did you clean out the tubing, and the housing fluid passages which the fittings screw into when swapping all the fittings? — hard water deposits do often re-dissolve in soft water!

 

[NitrateKillah]

Wow, that’s some extreme home water pressure! Honestly, you might want to put a pressure regulator before this RODI, or have a plumber see if you have a home pressure regulator which can be adjusted… the RODI housings, fittings, and tubing are typically only rated for around 85-90PSI (and your housings look to have some UV damage which inevitably makes them weaker!)


If RO product water TDS was low (good) with the new RO membrane, before fitting swap, then water isn’t channeling around any RO membrane seals!




I doubt it, I’ve gone through 3 auto shutoff valves in 11 years or so… they would either fail closed and provide little to no water to the system, or fail open and dump water out the waste line 24/7 if the system is pressurized while idle (all 3 of my ASO valves failed open)… this wouldn’t affect product water TDS!


You’ve got plenty of water pressure, and had low product water TDS with the new membrane… The only thing I can think of is this calcium in the lines… did you clean out the tubing, and the housing fluid passages which the fittings screw into when swapping all the fittings? — hard water deposits do often re-dissolve in soft water!

My idiot self left the RODI out in sun for many years, I stopped reefing, my success sucks at this. But I want to give it another 1 last time. I also changed out tubing also, I will try the fittings from BRS instead, hopefully that makes difference?

 

[UncommonSense]

My idiot self left the RODI out in sun for many years, I stopped reefing, my success sucks at this. But I want to give it another 1 last time. I also changed out tubing also, I will try the fittings from BRS instead, hopefully that makes difference?

Unless the fittings you bought are glazed in salt, I don’t think the 777TDS is reasonable… there’s something else afoot here…

Why not disconnect the RO product water tube from the DI cartridge inlet, and try flushing the system as RO only for an hour or so? (You’re technically supposed to flush out the RO membrane for an hour after install, anyways!)

 

[bristleworm]

Something as simple as changing the TDS meter batteries?

 

[RiptideAquaculture Verified Sponsor]

How old is the ASO valve? I’ve had those fail before and allow tap water to bypass the membrane and go straight into the DI stage. If you’re running above 60 PSI, I’d check the valve’s pressure rating to make sure it’s suitable for your setup. Depending on its rating, a high-pressure version might be worth looking into. https://www.aquariumwaterfilters.com/High-Pressure-Automatic-Shut-Off-Kit_p_154.html

 

[NitrateKillah]

Something as simple as changing the TDS meter batteries?

Already changed.

 

[RiptideAquaculture Verified Sponsor]

Already changed.

Have you cleaned the probe tips?

 

[NitrateKillah]

Have you cleaned the probe tips?

No I habe cleaned them.

 

[NitrateKillah]

How old is the ASO valve? I’ve had those fail before and allow tap water to bypass the membrane and go straight into the DI stage. If you’re running above 60 PSI, I’d check the valve’s pressure rating to make sure it’s suitable for your setup. Depending on its rating, a high-pressure version might be worth looking into. https://www.aquariumwaterfilters.com/High-Pressure-Automatic-Shut-Off-Kit_p_154.html

I think they unit is 20 years old I think? I ordered from Amazon and should be here tomorrow.