TDS Question

[acid_burn]

I run a 5 stage RO/DI...when I take a TDS reading in my holding can its 000ppm. Then I move the water to my mixing can and just by dumping it in there TDS jumped to 082ppm. Now i've mixed water in there before and there was some salt residue on the sides of the can when I dumped the fresh water in there. Could that be the reason the TDS jumped up? I took a reading in my main system and found a TDS of 062ppm. A friend of mine was telling me that I will get a TDS reading because of the salt but the reading in my mixing can was higher than my tank without even adding any salt yet??

Thanks,
Rich

 

[fishfreek]

Could that be the reason the TDS jumped up?

Yep. Having the container not be 100% free of dust/dirt will cause the TDS to increase. There is no need to take a TDS measurement of the tank as there are so many things in there that will affect TDS.

 

[acid_burn]

So a good cleaning of the mixing can should be done after each use?

Rich

 

[seaham358]

No cleaning needed as long as your only mixing salt water in there, salt residue is fine.

 

[quarryshark]

IMO if your TDS on your source water is that low, you are in great shape.
I would instead concern myself with the more basic water chems in your main. Such as PO4, nitrate, Alk, etc.

 

[fishfreek]

Kurt has it. If your starting water is that low then you have no need and no use of testing and knowing th TDS of the mixed water or of the Tank water.

The TDS meater is only good for testing the quality of your RO output water. Once the TDS starts to consistantly rise in the RO output you know your membranes are going bad and need replaced.