RODI and Ph

[Corwyn]

Hi group,

I just gor a new RODI system and wanted to test the water it's producing
before I started using it. My pH test says the water is 8.4.

Does that seem right?

Corwyn

 

[Anonymous]

Have you added the salt? If yes, then this is good PH. If not, it's too high. Seems to me that the RO water should be around 7.0, if memory serves.

HTH

Louey

 

[Corwyn]

No, I haven't added anything. This is water straight out of the unit.
I did make a mistake in that this is out of the RO side only.

The unit I got splits into two one for drinking water which only runs through the RO side.
The side that will fill the tank goes through the DI .

I haven't hooked up all the plumbing to the storage tank for the reef yet.


Does this make any difference?

Corwyn

 

[danmhippo]

I don't think RODI sets ph to neutral. My incoming tap has Ph range from 8.4 to 9.0. My output from RODI corrosponds to those ph range as well.

With that ph range, the TDS is still at 0ppm.

My RODI removed all PO4 (tap is 2.0 and RODI output is 0ppm), and NO3 (tap is 20ppm, and RODI output is 0ppm).

 

[danmhippo]

People install RODI after those water softner system will see their ph return to neutral, I believe.

 

[Anonymous]

I stand corrected. I just tested the ph of my RO/DI and it measured 7.65. I'm now on city water with no softner. My last house did have a water softener so what Dan said may be true. Or, was it distilled water that is 7.0? I can't remember for sure?

Surely someone out there knows for sure?

Louey

 

[ReefMon]

My understanding is that since RO/DI is pure water there is nothing to buffer it, making the pH is extremely difficult to measure.

Any sort of contamination will effect the pH whether it's tap water from rinsing off the probe or even CO2 absorbed from the atmosphere.

HTH
Glenn R