Measuring tds in mixing container

[slogan315]

I recently setup the rodi system that came with a used setup I bought. I’ve been using 5g containers to transfer saltwater, and am now using those to collect rodi as it’s made.

So with the containers empty but not rinsed of previous salt water, I filled them with rodi. The tds measurement was 28ppm in the containers and ~155 from the tap. I went and bought new filters, but before installing them tested in a clean cup, and the rodi output is at 1ppm….

my question is, if the rodi reads 0-1 exiting the filters, but becomes 28-30 in the contaminated containers, does that matter? I’m guessing that as long as it’s low tds from the filter and I get salinity right when mixing, the tds in between doesn’t matter. Just wanted to make sure.

 

[Saltyreef]

I recently setup the rodi system that came with a used setup I bought. I’ve been using 5g containers to transfer saltwater, and am now using those to collect rodi as it’s made.

So with the containers empty but not rinsed of previous salt water, I filled them with rodi. The tds measurement was 28ppm in the containers and ~155 from the tap. I went and bought new filters, but before installing them tested in a clean cup, and the rodi output is at 1ppm….

my question is, if the rodi reads 0-1 exiting the filters, but becomes 28-30 in the contaminated containers, does that matter? I’m guessing that as long as it’s low tds from the filter and I get salinity right when mixing, the tds in between doesn’t matter. Just wanted to make sure.

if your DI is outputting anything other than 0, you need to replace your resins and possibly more filters based on your findings.

Have you done a product to waste ratio to see what your flow restrictor in the waste line is set for?

Also, how about a inlet and outlet for your membrane?

Do you know if theres chlorine or co2 in the tap?

Fwiw even clean containers will leach some tds from my experience. Nothing i really worry about though.
100% if there was salt residue in there, your tds will be elevated.

 

[slogan315]

My resin color looks good still, but I suspect the membrane filter was never changed. So I’ll try changing that when it comes in.

Not sure on if I have chlorine or co2, but I’ll look into it. Guessing more co2 just lowers your ph, and chlorine will kill beneficial bacteria?

haven’t done a waste ratio yet.

going to use what I made for this water change, but have filters replace before the next.

Thanks for the info @Saltyreef

 

[brclark82]

the salt residue in your bucket will increase TDS very quickly so unless you give it a good rinse and dry between then you need to test a clean cup if you want to check tds. it's obviously not a a problem to leave the salt residue in the bucket since you will be adding additional salt anyway so I would just not worry about it and spot check a cup of water occasionally

 

[Randy Holmes-Farley Verified Community Expert]

I'd ignore the TDS in mixing containers. There are a variety of reasons it may rise a bit, and none are likely a concern.