Help understanding ammonia test, hanna

[125mph]

I have a QT set up, and first time using Hanna ammonia checker, I get 0.65 reading. I quickly do a 70% water change... next day, I check and its 0.55. I put in a seachem ammonia badge and reading says around 0.02ppm. So my guess is the badge is showing toxic ammonia while hanna shows total?

I read more on the hanna documentation, and you have to calcuate the toxic ammonia via pH and temp... So based on a 78'F, only about 5.8% of the ammonia is toxic.. So at 0.55ppm of total ammonia, im looking at around 0.03ppm toxic ammonia, so I'm pretty safe?

Is my understanding correct? And I should do a water change if it gets to about 0.1 - 0.15ppm toxic ammonia?

Does the API test measure free or toxic?

 

[Formulator]

I have a QT set up, and first time using Hanna ammonia checker, I get 0.65 reading. I quickly do a 70% water change... next day, I check and its 0.55. I put in a seachem ammonia badge and reading says around 0.02ppm. So my guess is the badge is showing toxic ammonia while hanna shows total?

I read more on the hanna documentation, and you have to calcuate the toxic ammonia via pH and temp... So based on a 78'F, only about 5.8% of the ammonia is toxic.. So at 0.55ppm of total ammonia, im looking at around 0.03ppm toxic ammonia, so I'm pretty safe?

Is my understanding correct? And I should do a water change if it gets to about 0.1 - 0.15ppm toxic ammonia?

Does the API test measure free or toxic?

Your understanding is correct. Hannah will measure total ammonia nitrogen (NH3 and NH4+). The badge just measures NH3, the toxic one. Your calculations are accurate.

By the way, you really have nothing to worry about either way. Randy recently had a nice thread about ammonia toxicity and how we hobbyists vastly overestimate the toxicity:

Thread 'How toxic is ammonia, really?'
https://www.reef2reef.com/threads/how-toxic-is-ammonia-really.1030601/

 

[kvansloo]

I have not tested ammonia since my tank cycled 15 years ago.

 

[Randy Holmes-Farley Verified Community Expert]

I have a QT set up, and first time using Hanna ammonia checker, I get 0.65 reading. I quickly do a 70% water change... next day, I check and its 0.55. I put in a seachem ammonia badge and reading says around 0.02ppm. So my guess is the badge is showing toxic ammonia while hanna shows total?

I read more on the hanna documentation, and you have to calcuate the toxic ammonia via pH and temp... So based on a 78'F, only about 5.8% of the ammonia is toxic.. So at 0.55ppm of total ammonia, im looking at around 0.03ppm toxic ammonia, so I'm pretty safe?

Is my understanding correct? And I should do a water change if it gets to about 0.1 - 0.15ppm toxic ammonia?

Does the API test measure free or toxic?

Nearly all tests we use measure total ammonia, and doing calculations to get to NH3 is not worth the bother, IMO, unless you are trying to understand unusual scenarios like shipping bags.