Finding the Problem with ACO Ammonia Test Strips

[modified lung]

On 9/4/2022 at 7:53 AM, Guppysnail said:

@modified lung thank you for this explanation. Now I also understand why ammonia is more toxic at higher ph. I really appreciate your time and all you put into this article. 

Just trying to cull the existential boredom.  👍

[Pepere]

@modified lung, Am I correct in thinking that if I take a sample of water with total ammonia of 1 ppm and raise the ph of the sample to 10, then the Aquarium Co op ammonia test strip should read a similar result as all of the ammonium would be converted to NH3 and hence readcout as total ammonia?

[modified lung]

On 9/4/2022 at 8:31 AM, Pepere said:

@modified lung, Am I correct in thinking that if I take a sample of water with total ammonia of 1 ppm and raise the ph of the sample to 10, then the Aquarium Co op ammonia test strip should read a similar result as all of the ammonium would be converted to NH3 and hence readcout as total ammonia?

That's exactly what I did and exactly what happened. The reading on the ACO strip was crazy accurate too. Like the best strip I've ever seen.

[Kiefer]

On 9/3/2022 at 3:29 PM, Pepere said:

Sure, but if that is the case the detected range for free ammonia needs to be a whole heck of a lot lower than starting at 0.5 ppm free ammonia which is highly toxic to fish.

Depends how we define highly. 0.5ppm free ammonia is where most aquaculture studies I've read say you start seeing hazards from chronic exposure. So if your aquarium spikes to 0.5 and you do something about it quickly there's not that much of a problem with it, if it was from a one-off event like a fish dying or a kid dumping a container of food in. If you're sitting at 0.5 for days or weeks on end you are going to start seeing damage build up. But if your aquarium spikes to 1, or 2ppm, you need to do something or you could wake up to dying fish.

But that varies quite a bit based on species. Pond/lake dwelling species can be a lot hardier, one study I vaguely recall showed that for tilapia, the king of garbage water fish, chronic damage didn't start until almost 2ppm free ammonia which is acutely toxic to many other fish, and I am all sure we have seen of or heard about a goldfish living for 5 or 10 years in a toxic nitrogen soup. Then you have fish that mostly live in acidic riparian systems where free ammonia basically can't exist like cardinal tetras who start showing chronic damage at 0.1ppm, and the same is true for many saltwater fish (and exacerbated by the fact that saltwater pH is inherently high so you don't get much help from ionization).

I guess it also depends how you interpret "caution." Me? I see caution and read "Do something." For other people, especially if you're busy with kids or whatever I can totally see people reading that caution as "Do something about it this weekend." Which probably wouldn't kill most fish at 0.5ppm, but could easily kill fish at 1 or 2ppm.

ANY ammonia level should be 'caution' in terms of your filter not being sufficient/stocking too high, even though it might not be acutely or even chronically hazardous to the fish at persistent but low levels. But it's hard to put all of that information on the back of a bottle especially when you can't get most people to read one or two lines these days.

[nabokovfan87]

On 9/4/2022 at 7:23 AM, modified lung said:

On 9/4/2022 at 5:34 AM, Guppysnail said:

I don’t know the difference between the two Nh 3-4  would you mind explaining so I can learn?

Ammonia (NH3) = N-H-H-H

Ammonium (NH4+) = N-H-H-H-H

pH is determined by how much free H+ (hydrogen ions) is in the water ("free" means it's not attached to anything else, it's just by itself).

Lower pH means there's more free H+.

When there's a lot of free H+ flying around, some of it attaches to NH3 which turns it into NH4+. That's why there's less NH3 at low pH.

The extra H in ammonium gives it a positive charge (+) which makes it less toxic because that makes it more difficult to be absorbed into a fish's bloodstream. 

The lethal concentration (LC) of ammonia (NH3) is usually somewhere between 1 and 3 ppm over 2 or 3 days of exposure. The lowest fish LC I know of is for cardinal tetras which is between 0.3 and 0.4 ppm over 4 days of exposure.

The LC of ammonium (NH4+) is usually around 40 to 50 ppm.

I hope that all made sense.

I totally enjoyed reading this and the explanation.  Much appreciated.  Things like this help us all to really understand what is going on in the tanks chemically or biologically with all these microscopic bits going on.

On 9/4/2022 at 7:23 AM, modified lung said:

You could say the 20 minute test is better but when I'm at home I'm impatient and would rather wait 30 seconds even if there's a bigger margin for error. I just have to not be too lazy to set a timer ...again.

If you mean after your cycle should already be established, nitrite-oxidizing bacteria are a lot more sensitive to basically everything compared the ammonia-oxidizing bacteria. That could be why you have nitrite show up but never ammonia.

I figured this was why.... my correlation being that the first part of cycling a tank is very easy to get going, but going from nitrite into nitrate takes a little bit of time.  Thank you for the clarification!

[modified lung]

On 9/4/2022 at 11:17 AM, Kiefer said:

0.5ppm free ammonia is where most aquaculture studies I've read say you start seeing hazards from chronic exposure.

It's 0.05 ppm NH3, not 0.5 ppm, where chronic often starts. The EPA criteria for chronic exposure is between 0.015 and 0.025 ppm NH3 depending on pH and temp. A lot of studies report LC50s in TA or TAN so it can get confusing.

On 9/4/2022 at 11:17 AM, Kiefer said:

cardinal tetras who start showing chronic damage at 0.1ppm

The 96 hour LC50 (acute) for cardinal tetras is between 0.3 and 0.4 ppm NH3. The 96 hour LC10 is between 0.02 and 0.2 ppm NH3. Chronic is usually considered to be 30 days of exposure so those numbers could be a lot lower—usually 5 to 10% of the 96h LC50 so 0.015 to 0.04 ppm NH3.

study 1

study 2 (pdf)

Cardinal testas are an extreme example though. But others aren't far off. In study 2 only 4 of the 11 species studied had an LC50 above 1.0 ppm NH3 (converted to ppm from mM).

Tilapia are well known to be very hardy and goldfish can actually detoxify a good amount of ammonia inside their bodies. Cyprinids in general seem a bit more hardy than others.

But most LC studies only expose fish to one stressor. The numbers fall fast when exposed to multiple stressors.

I admit it could have said "many" or "some" fish. But that's not really a big deal.

Edited September 4, 2022 by modified lung

[Pepere]

On 9/4/2022 at 11:39 AM, modified lung said:

That's exactly what I did and exactly what happened. The reading on the ACO strip was crazy accurate too. Like the best strip I've ever seen.

I wonder if the corollary is true too with the API wet test.  
 

you mentioned bottle 1 solution is designed to raise ph so all of the ammonia is NH3 free ammonia which bottle 2 detects.

 

can you use just bottle 2 to find out how much NH3 is in your tank?

[modified lung]

On 9/4/2022 at 2:37 PM, Pepere said:

I wonder if the corollary is true too with the API wet test.  
 

you mentioned bottle 1 solution is designed to raise ph so all of the ammonia is NH3 free ammonia which bottle 2 detects.

 

can you use just bottle 2 to find out how much NH3 is in your tank?

Theoretically it would work but I've never tried it. You can use the 2nd nitrate bottle to do a nitrite test too but it's a little off.

Edited September 5, 2022 by modified lung

[Tomdobbins]

ME?? IM surprised CORY SIR hasn't run the test himself....Didn't he test them... I HOPE he let's us know what's what.... Maybe THE people who make them know....

[modified lung]

On 9/6/2022 at 11:42 PM, Tomdobbins said:

ME?? IM surprised CORY SIR hasn't run the test himself....Didn't he test them... I HOPE he let's us know what's what.... Maybe THE people who make them know....

If it's a mistake from the manufacturer, he can't be expected to test every batch of strips.

Or he could have intended them to only test unionized ammonia which would be completely fine. But then I'd like to know the reasoning behind the ranges on the color scale on the bottle. He might have a good reason for all I know.

Honestly, if the ACO ammonia strips are working as @Cory intended (meaning they won't change) and I can find a good, cheap way to increase the pH of water samples to 10 which would let me see chronic levels of unionized ammonia, I'd make my employer completely switch over to them. They are otherwise that good.