Salifert NH3 or NH4??

[ReeferHolland]

Hi, So my LFS just sold me this salifert testing kit when I bought my new tank.


Is this the correct one for testing ammonia?
I can't find this test on any website. I only find this test everywhere:


NH4 vs NH3? Whats the difference? Or just all the same with a new package? Which one to use for new tanks?

 

[fishski13]

its the same thing, people just use NH3 and NH4 interchangeably but NH3 is the dangerous form of ammonia found in water while NH4 is the ionized part which isnt as dangerous.