Purified water - what questions do I ask?

[SunfishFun]

For top-off & kalk water for my 60 gal tank I currently use RO water from LFS, which is 50 cents/gal and not nearby. I searched Reefs.org and found pros of buying a home RO unit, but today I saw a machine at grocery store which sounds good. For 29 cents/gal water is filtered through carbon, RO, and UV treated. Someone comes weekly to test the output water. It uses my local tapwater as source water.

I can phone the company or go to website for more info, but what questions do I ask? Short of whether water contains copper which I know is bad for reef, I have no idea what to ask them, my water company, water stores, or how to compare bottled purified water!

I welcome any info!

 

[Lunchbucket]

yeah my local grocery store sells it like that too. i used it for a couple months till i got my own ro/di unit. i tested it w/ a tds monitor and it was at 14ppm. not bad...don't know about the contents though but it can't be much.

test it and see what it is like. or get a read out from them when they come by to test it

later
Lunchbucket

 

[SunfishFun]

What do I test for?
I can test freshwater w/ saltwater test kits?
TDS = Total dissolved solids? What does this tell me?
What I meant by my first message is that I do not know what to do even if I have a printout of water quality. Sorry!

 

[Goldmoon]

Hmm we bought some RO water at a Kroger store and tested the phosphate.
They were higher then the normal test could grade. On that test kit if no phospate it stays clear, and the more you have it turns blue. That water was the deepest blue I ever saw... Be carefull if you are using grocery water. Buy one gallon and do some testing first.
Just a thought.