Ro Di TDS ppm Strange reading.

[Antonio.dejesus]

I just bought a TDS meter and wanted to test it out. I made a connection in the following way, the IN was just before it enters the RO system, and the OUT is connected right after the sediment and carbon filter(wanted to see how the sediment filter and carbon are doing). The reading for the OUT what's higher than the IN.

After that, I connected the OUT right after the membrane and the reading was(8ppm) better since it said that it was lower than the IN, how its supposed to be. So what can explain that my reading after the sediment and carbon is higher than the IN?

 

[GoVols]

@Antonio.dejesus
Does this video help?

 

[Antonio.dejesus]

@Antonio.dejesus
Does this video help?

Already saw it before I did it.

 

[GoVols]

Already saw it before I did it.

(lol)
I run one meter that reads the water after the DI resin. When it hits 1, I change out the sentiment / carbon block and DI resin.

Would you like some more help to come in and assist you?

 

[Battlecorals Verified Sponsor]

I just bought a TDS meter and wanted to test it out. I made a connection in the following way, the IN was just before it enters the RO system, and the OUT is connected right after the sediment and carbon filter(wanted to see how the sediment filter and carbon are doing). The reading for the OUT what's higher than the IN.

After that, I connected the OUT right after the membrane and the reading was(8ppm) better since it said that it was lower than the IN, how its supposed to be. So what can explain that my reading after the sediment and carbon is higher than the IN?

The sediment and carbon filters actually do not reduce tds in any way. They only prepare the water to be filtered by the membrane.

How much higher was the reading pre membrane/ post sediment than the tap?

 

[Antonio.dejesus]

The sediment and carbon filters actually do not reduce tds in any way. They only prepare the water to be filtered by the membrane.

How much higher was the reading pre membrane/ post sediment than the tap?

The tap water was around 350 more or less. I just got my replacement filters. The tds after the entire Process is 0 tds.

 

[Antonio.dejesus]

The sediment and carbon filters actually do not reduce tds in any way. They only prepare the water to be filtered by the membrane.

How much higher was the reading pre membrane/ post sediment than the tap?

And the reading after sediment and carbon was around 10 to 20 higher than tap .I'll have to check again cause I dont remember well. After membrane was around 7 to 9.

 

[Randy Holmes-Farley Verified Community Expert]

The sediment and carbon filters actually do not reduce tds in any way. They only prepare the water to be filtered by the membrane.

How much higher was the reading pre membrane/ post sediment than the tap?

They can even raise tds. Breaking chloramine into ammonia and chloride, for example.

 

[Randy Holmes-Farley Verified Community Expert]

And the reading after sediment and carbon was around 10 to 20 higher than tap .I'll have to check again cause I dont remember well. After membrane was around 7 to 9.

A rise that big is likely just a miscalibration or temperature difference between the two TDS meters. For example, if the water warms up a bit as it passes through the filters, the reading will rise as inline TDS meters are not temperature compensated (and probably not super accurately calibrated either).

It's no concern anyway, and is no indication of any problem.

 

[Antonio.dejesus]

Thanks