ammonia test kits!

[EdsonFOWLR]

What is the difference between a freshwater ammonia test kit and a saltwater one?

[mrhasan]

What is the difference between a freshwater ammonia test kit and a saltwater one?

Same thing. The color chart is a bit different (yellow for freshwater while a slight green tint for saltwater).

[EdsonFOWLR]

So am I ok using my freshwater one (Hagen one) for my salt tank?

[gregzz4]

So am I ok using my freshwater one (Hagen one) for my salt tank?
That depends on which Nutrafin kit you have
If it's capable of fresh and salt, it will be # A7855
If it's # A7820 it's only good for fresh