Can I use my api saltwater test kit on fresh water?

[jcurella]

I've been using a table top RO system for many years now which has a finite life span. My water quality just doesn't seem to be what it used to be. i'm wondering if my RO system has reached it's limit.
The lfs guy said I could test my RO water with my saltwater test kit. Does this seem legit? Or is there a difference between saltwater kits and freshwater kits?
Thanks,
Joe

 

[bertoni]

Some tests will be fine. What parameters are you checking? I'd use a TDS meter to check RO/DI water, in any case. They can be very accurate and don't cost very much, all in all.

 

[Potatohead]

I researched this a while back, the only difference is the colour of the nitrate test, there are different colour charts for fresh and salt. Also the gh test is useless for salt, obviously.

I agree a cheapish TDS meter is the way to go for this, though.

 

[jcurella]

Thanks for the replies. I was unfamiliar with tds testers. But I looked them up, and they go as cheap as 12 bucks online. Great idea. I will definitely buy one for this.
Thanks again!

 

[bertoni]

You're welcome. Good luck!

 

[nereefpat]

You can also find inline TDS meters to plug into the RO unit. Then you always know while the unit is running. They aren't that expensive either.

I have the 30$ one in the middle of the page.

https://airwaterice.com/tds-ph-meters.html

Edit: grammar

 

[ericarenee]

I do all the time.. With the noted above freshwater test card ..