TDS of Distilled Water?

[TygGer]

Has anyone used a TDS meter on distilled water?

And while you're reading this, maybe you can answer this also...

What determines if the water is suitable for using in a SW aquarium?

 

[darb2]

The tds of ro/di water should read 0 ppm.
My well water reads 70 ppm, and I have a cyano outbreak in my fowler. So I got a ro unit. I just ordered a tds meter, so I,m not sure how low ro water is.
here is a basic guideline for DRINKING
0-50 Ideal ro/di water
50-170 acceptable water
170 hard water
200-300 marginally acceptable
300-500 unpleasant
over 500 EPA contamination level
If I am gettting cyano at 70, then I would make it lower than that

 

[kwan]

In an other post, I registered a reading of 60 ppm from my RO water. My SW in the main tank read 650 ppm. What should we expect in the SW? I know the saltmix will add things back into the RO water, but 650 sounds pretty high to me.

 

[BillyZ]

yea, doing a TDS reading of the water IN your tank will be quite high! The salt, Calcium, and myriad of other things that you do actually want in your water, will bring that TDS reading very high, as you see.

I believe you will typically get as darb described for your RO water. Obviously, the lower the TDS reading on your filtered water the better. The lower the TDS reading the less contaminants you're adding to your tank.