Can API Ammonia, Nitrate, Nitrite Reef/Marine tests be used on fresh water?

[NickRummy]

I just purchased the Reef Master and Saltwater Master kits from API for a starting point on testing kits for my reef tank. I also have a freshwater Tetra tank that I was planning on using the Ammonia, Nitrite and Nitrate tests for. It looks like all of the places I've seen the kits sold individually it says they are good for freshwater and saltwater but in the kits the color charts say for saltwater specifically. Do the freshwater/saltwater tests have (2) different color charts or something? If so is there a place I can get those? I need to order a lower range PH test kit for the FW tank anyhow.

Phosphates would carbonate hardness would be nice to use as well.

 

[jsoong]

My API individual kits have 2 cards, one for FW, one for SW. The colors are slightly different, but not off by 1 or 2 spots. If you are just going for ball-park figures, the SW cards would be fine. Also, zero reads the same in both, so for NH3/NO2 when you only want to know if it is zero, you can use the SW card.

 

[NickRummy]

Thanks! I did some searching and found this. I saved them onto my iPhone and compared to the saltwater cards I have and they are surprisingly close. This should work out pretty well.

API Test Cards

 

[uscamaro]

That is a huge help, I just bookmarked that site.

 

[Kurt_Nelson]

Great find!

Just be aware though... depending on how the cards were scanned and how your monitor is setup, the colors shown may or may not be representative of the colors actually printed on the cards that come with the kit. AND... the colors that come printed on the cards can change from time to time. My last API pH test kit had a different color card with it than previous years!