Ammonium - PH4

[TonapahNorth]

I have a Seneye Reef Monitor and its new. I'm pleased with its utility so far; however, it tracks Ammonium (PH4), as opposed to deadly ammonia (PH3), which I am understanding to be completely harmless. How is this useful to know?

Thanks
Tona

 

[Rob Lion]

the seneye measures Ammonia (NH3) which is the toxic compound. The seneye also Calculates (not measures) the Ammonium (NH4) in the tank, based on your Ammonia / O2 / pH.

Within your reef tank, Ammonia freely gains and loses an extra Hydrogen ion, so the Ammonia changes to Ammonium and back to Ammonia many many times, depending on your pH and availability of free Hydrogen ions.

Ammonium is useful to know, as it will indicate how much Ammonia potential your reef tank currently has.

Normal healthy tanks I think will normally be registering about 8ppb (0.008 ppm) NH4 to zero NH3. depending on pH and Co2 in your water.

Both NH3 and NH4 are natural by-products from fish eating and breathing / waste breakdown. The de-nitrifing bacteria in your tank breaks down NH3 to Nitrites and then Nitrates and then in very low oxygen areas of your tank into Nitrogen gas. NH4 isn't broken down until it loses the extra Hydrogen ion to become NH3.

The seneye also calculates Oxygen too, O2 . Normal expected readings would be 8-10 ppm

 

[TonapahNorth]

the seneye measures Ammonia (NH3) which is the toxic compound. The seneye also Calculates (not measures) the Ammonium (NH4) in the tank, based on your Ammonia / O2 / pH.

Within your reef tank, Ammonia freely gains and loses an extra Hydrogen ion, so the Ammonia changes to Ammonium and back to Ammonia many many times, depending on your pH and availability of free Hydrogen ions.

Ammonium is useful to know, as it will indicate how much Ammonia potential your reef tank currently has.

Normal healthy tanks I think will normally be registering about 8ppb (0.008 ppm) NH4 to zero NH3. depending on pH and Co2 in your water.

This is very helpful information. Thank you very much.

If the hydrogen molecule freely changes between ammonia and ammonium, why is there zeros on the Ammonia detection? Is it so rapidly occurring that it doesn't register on the Seneye?

Admittedly, the tank I have this on is only a couple weeks old but I'm reading between .001 and .005 Ammonia and about .11 Ammonium. As it starts to creep up I do a water change. I'm sure it's just cycling but I feel like I want to chase numbers.

 

[Rob Lion]

If the hydrogen molecule freely changes between ammonia and ammonium, why is there zeros on the Ammonia detection? Is it so rapidly occurring that it doesn't register on the Seneye?

Yes it happens many times a second, but of course not all Ammonia changes to Ammonium at the same time!

How are you cycling your tank?
Live rock?
Added bacteria?
Feeding?
Fish?
Are you testing for Nitrites?
Are you testing for Nitrates?

I'm not sure you should be doing water changes until the cycle is complete, but that depends on the way you are cycling.

 

[TonapahNorth]

Its intended to be a frag QT tank as soon as it's ready. Maybe I'm doing it wrong.

Its live sand, dry rock, added bacteria, and two small clowns from my main display. I have tested nitrites and nitrates but not recently. I've just been watching the Seneye.

Tona

 

[Randy Holmes-Farley Verified Community Expert]

I have a Seneye Reef Monitor and its new. I'm pleased with its utility so far; however, it tracks Ammonium (PH4), as opposed to deadly ammonia (PH3), which I am understanding to be completely harmless. How is this useful to know?

Thanks
Tona

Let me just clarify. It isn't really true that ammonium is not toxic. If it got into the animal, it would be. It is just that the NH4+ form doesn't cross lipid membranes nearly as readily as the uncharged NH3 form.

On one side the the membrane 9say, the gills), you have NH3 (ammonia) and NH4+ (ammonium). Those beat against the gills trying to get in, but only NH3 crosses. So it is the NH3 concentration at the gill surface that causes the entry and toxicity of ammonia. ore there means more gets in.

As Rob noted, NH3 and NH4+ are in instantaneous equilibrium with the ratio depending only on pH (assuming unchanged salinity, etc.). So you can know how much NH3 is present from total ammonia plus ammonium and pH. I'm not actually sure whether the Seneye actually measures NH3 or NH4+ (I'd guess NH3), but it doesn't matter to a user which it is since the other can be calculated by the device and the produced answer does not tell you what is actually detected.

 

[TonapahNorth]

Thank you. I'm wrecked and in the ditch in the weeds. j/k

I think I understand what you're saying. From a practical standpoint, NH4+ (ammonium) is important to know because it is "potential" NH3. So it helps us know where our attention should be in ensuring the cycle is active.

I believe that both of the explanations help me to understand the workings of the Seneye monitor, which displays O2 potential, pH, and NH3. Their interrelationships seem more valuable to me now.

 

[Randy Holmes-Farley Verified Community Expert]

This has more on ammonia:

Ammonia and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2007-02/rhf/index.php

 

[TonapahNorth]

Are there conclusions to be made if NH4 is increasing, pH is decreasing, NH3 is steady and O2 is steady?

Specifically over the last 16 hours, NH4 is rising from 11 and is now at 20. pH is usually around 8.35 but has dropped to 7.95. NH3 is at steady between 7 and 8ppm. Same with O2 - steady at 8.

I know I can't do much until NH3 is steady at 0. But maybe I can understand what's happening here.

 

[Rob Lion]

Your pH will naturally fluctuate throughout the day/night, one of the main reasons is the amount of Carbon Dioxide (CO2) in your tank. During the daylight hours, your algae and corals consume CO2 and expel Oxygen (O2), this raises your pH to a higher number. During the night less CO2 is absorbed so the pH generally drops. That is why many people operate their refugiums on a reverse lighting schedule, to light up the refugiums at night to compensate for the lack of CO2 absorption in their main tanks, but of course our sump tanks are smaller than our display tanks and holds less corals and possibly algae, so it never normally equals out, but still helps out.

As pH fails, the waters loses H+ ions that then combine with NH3 and so NH4+ increases, so you tend to see as pH falls, NH4 rises. Don't forget, the difference from Ammonia NH3 and Ammonium NH4+ is the H+ , the single Hydrogen ion, it can only be in one place at a time.

 

[TbyZ]

As can be seen in Figure 2, in an average range of pH in the seawater, the percentage of NH4+ is higher (82-97%) compared to that of NH3 (3-18%).

http://www.advancedaquarist.com/2011/4/chemistry

 

[TbyZ]

that image's address

http://www.advancedaquarist.com/2011/4/chemistry_album/Fig_2.jpg/image_preview

 

[Randy Holmes-Farley Verified Community Expert]

Are there conclusions to be made if NH4 is increasing, pH is decreasing, NH3 is steady and O2 is steady?

Specifically over the last 16 hours, NH4 is rising from 11 and is now at 20. pH is usually around 8.35 but has dropped to 7.95. NH3 is at steady between 7 and 8ppm. Same with O2 - steady at 8.

I know I can't do much until NH3 is steady at 0. But maybe I can understand what's happening here.

It means total ammonia is on the rise.