Does Api Fw Work In Saltwater?

[techen]

The answer? I think yes.
 
As far as I can see, My RO gives me a reading of zero. Which is what it should be.
 
But for my Saltwater it goes orange. Which by the algae that's slowly forming in my tank would be true.
 
So am sure it does the job, Unsure how close it is though.

 

[techen]

And in saying that, I have a large problem with nitrates....
 

 

[Donya]

In general, yes, but the color scales aren't the same (although they are fairly close on some kits). The ammonia kit is probably the biggest pain color-wise due to the cloudiness when used on sw. Nitrate differs a reasonable amount on the color scales too. 5 and 10ppm are hard to tell apart for sw, because 10ppm sw looks like 5ppm fw. 20ppm sw looks like 10ppm fw.

 

[techen]

Well my LFS tested my water with the red sea test kit. He said it came back as 2 parts per litre I think? Almost the lowest the chart goes.

So I really don't think I have a problem with nitrates.

 

[wayne1421]

I contacted API asking if the Tropical test kit would work on saltwater as I am in the process of starting a marine tank and API sent me the salt water chart cards so that I can use my remaining test kit for the marine tank.
 
Donya is right about the ammonia, i used it this morning and couldn't believe how cloudy it was, thought I was doing something wrong

 

[Donya]

couldn't believe how cloudy it was, thought I was doing something wrong

 
The easiest work-around for the ammonia cloudiness if it makes reading the numbers hard is to compare to a tube tested with freshly mixed salted RO. That way you have a known zero. I've used the kits for years and still have to do that periodically.

 

[xXLeafeonXx]

I wouldn't use API for salwater.