Ammonia is our Friend: thoughts needed

[SDchris]

I see a major sticking point being wording.
Live rock, sand, macro algae, refug,.... are all described as being a "filter"
Filter = good
So common sense would suggest.
More filter = more good

If when talking about inorganic N it is changed to:
Filter = competitor
And when talking about organic N processing it is changed to:
Filter = sewerage treatment
Then instantly the mentality towards the way you design and manage what you have changes.

 

[Jari]

An approximation is that fish release about 90% of the nitrogen they consume as ammonia. That nitrogen comes from the protein in the food they eat. The amount of protein in food is relatively easy to find out.

One additional point here is the temporal pattern of ammonia once the tank matures, dosing mainly during the day as in the nature. In the reefs this is also driven by migratory fish, but might nevertheless have some relevance in reef tanks as well.

 

[Hans-Werner]

Live rock is fine, but the goal of it is to have surfaces resistant to algae, not to add bacteria.

Why not add bacteria? The big advantage of live rock is that it introduces complete, working microbiomes. To reduce bacteria to nitrifying bacteria is not a good approach in my eyes, not for good and not for bad. I doubt that live rock introduces much nitrifying bacteria, maybe nitrifying archaea (may seem like hairsplitting). For nitrifying bacteria the ammonium concentrations in NSW are too low. It is mainly archaea that do the nitrification in NSW and oligotrophic tanks.

Calcareous surfaces may have a dual function: Being substrate for bacteria and buffering phosphate. In fact the large surface of a coral sand substrate may act more as a source and buffer for phosphate than as substrate for nitrifyers, especially when starting a reef tank. Phosphate concentration and phosphate supply of coral sand usually is quite high.

One observation I’ve noticed is that most (not all) nuisance algae require at least a hard edge or porous material to cling to. Smooth surfaces such as acrylics and plastics don’t seem to be great real estate. Coralline however loves these smooth surfaces. I can put a picece of plastic in my tank and see coralline within 2 weeks.

I say this because I’ve pondered doing a very similar set up, except with no rock and only plastics, adding corals first and a source of nitrogen and phosphorus.

Plastics are lipophilic in contrast to many other surfaces. Lipophilic surfaces attract bacteria. Most macroalgae including coralline algae need some bacterial "companions" that produce vitamins and/or other growth promoting substances the algal parners need. The algal partners give organic carbon compounds (slimy surface) to the bacteria in exchange.

Is it true that there is nothing we can do about that? I think the experiment would be even more compelling with an antibiotic, though I’m not sure how livestock would fare in a sterile environment, aside from the impact to nitrogen cycle.

Archaea are not sensitive to the usal antibiotics. I think in many tanks antibiotics have been used unknowingly to eradicate cyanobacteria and not always with severe detrimental effects or maybe sometimes without detrimental effects at all. Archaea are a much underestimated and often unknown part of the microbial communities, especially inside organisms like sponges or corals.

Having equal or more ammonia uptake will lead to zero NO3. The only way around that is to dose something daily, just enough to balance the few ppm of NO3 needed. Possible in a forever changing environment?

Who says a few ppm of NO3 are needed? I think this should be proven, maybe by RHF's experiment.

As far as possible ideas for the article. For me it would be interesting to see the time frames in which corals can consume NH3 compared to nitrifiers if that is even testable.

This is already known. The "time frames" (and more important the concentrations) at which in biochemistry uptake of something occurs is described by uptake kinetics which is typically a Michaelis-Menten kinetics. You can find uptake kinetics of Stylophora here.

Nitrifying bacteria need much higher ammonia/ammonium concentrations than corals to show any uptake. Here mainly archaea are relevant. I know there are articles around comparing uptake of ammonium by ammonia oxidizing bacteria AOB with that of ammonia oxidizing archaea AOA, but I am not sure that such comparisons are of too much help. Conditions in reef tanks are complex with spatial and temporal patchiness of nutrients. For example AOA may sit at places where ammonia is produced, for example inside sponges or at other filter feeders. Corals may benefit from fish and coral crabs hiding between branches.

 

[taricha]

I went 5 years without adding ANYTHING but a few pinches of food, in total maybe 6-10 times over that period. A tang, coral beuty and hawkfish and snails and corals lived the entire time.

That's the first actual persuasive evidence that I've seen for N-fixation in a hobby system being significant.

(sorry, slight off-topic)

 

[Dburr1014]

Who says a few ppm of NO3 are needed? I think this should be proven, maybe by RHF's experiment.

Just to answer this one question because it is directed to me; everyone on this forum. Well, maybe not everyone, but 99% of the people. Just a quick search with the search button and you will get hundreds of hits.

To give context, my tank literally runs zero on my hanna, for months. I feed my fish, they feed my coral, nothing is dying.

This would be a wonderful experiment. I would love to see it. I would have no idea how to implement it though.

 

[BeanAnimal]

That's the first actual persuasive evidence that I've seen for N-fixation in a hobby system being significant.

(sorry, slight off-topic)

Yes - there was enough stored N and P to self feed the system for half a decade

 

[Hans-Werner]

Just to answer this one question because it is directed to me; everyone on this forum. Well, maybe not everyone, but 99% of the people.

Yes, but 99 % also think N = NO3 which just is not true. Also most reefers have no idea of the uptake kinetics of nitrate and think they know a few ppm are necessary but "a few" ppm means NO3 uptake is more than saturated.

Frequently also NO3 and PO4 or "nutrients" are summed up. So the resulting image is very blurred.

It would be really interesting to make experiments at constant high PO4 concentrations varying NO3 concentrations only, if concentration over 1 ppm NO3 have an additional effect or not.

 

[taricha]

Yes - there was enough stored N and P to self feed the system for half a decade

Actually, the N-fixation idea is that if there's no usable nitrogen available and there is available energy (photosynthesis = organic carbon = energy) then a few organisms can just use N2 from the air - expend a LOT of energy, and bust the N2 triple bond to get usable Nitrogen for cell growth.
People talk about it, but it's so energy intensive, and there are so many other ways to get N, it may not actually happen much in aquaria.

But I agree, the system likely just cycled P over and over.

 

[BeanAnimal]

Actually, the N-fixation idea is that if there's no usable nitrogen available and there is available energy (photosynthesis = organic carbon = energy) then a few organisms can just use N2 from the air - expend a LOT of energy, and bust the N2 triple bond to get usable Nitrogen for cell growth.
People talk about it, but it's so energy intensive, and there are so many other ways to get N, it may not actually happen much in aquaria.

But I agree, the system likely just cycled P over and over.

Ahh - interesting. I am not so sure it cycled P over and over. Possible, as it was certainly not zero when I finally got around to testing it on year 5... I would have no way to prove or disprove, but maybe at some point it did transition from simply recycling P to an N-fixation model. There was certainly a steady supply of algae, but maybe that dictates that there was still a steady supply of P?

Sorry for the sidetrack - this really has little to do with Randy's thoughts here.

 

[ReeferZ1227]

Yes, but 99 % also think N = NO3 which just is not true. Also most reefers have no idea of the uptake kinetics of nitrate and think they know a few ppm are necessary but "a few" ppm means NO3 uptake is more than saturated.

Frequently also NO3 and PO4 or "nutrients" are summed up. So the resulting image is very blurred.

It would be really interesting to make experiments at constant high PO4 concentrations varying NO3 concentrations only, if concentration over 1 ppm NO3 have an additional effect or not.

Unscientifically lower NO3 leads to paling SPS in my tank with a stable po4 of > .05-.1

 

[Randy Holmes-Farley]

My opinion on nitrate is that it is insurance of adequate N bioavailability. It is not needed if other sources are sufficient, but since we cannot readily measure those, having a few ppm nitrate make it clear there is enough.

 

[ReeferZ1227]

My opinion on nitrate is that it is insurance of adequate N bioavailability. It is not needed if other sources are sufficient, but since we cannot readily measure those, having a few ppm nitrate make it clear there is enough.

Healthy and sustaining being sufficient? If i want colorful coral i notice an impact under 5, granted measuring with salifert which is ballpark color chart +/- 5ppm IMO. I think this is almost "common thought" amongst SPS keepers currently.

What would be interesting is to run it down low, dosing ammonium for a few ppm NO3 maintenance and see the impact on color/vibrance of SPS to confirm "sufficiency" at a few ppm via ammonium.

 

[Randy Holmes-Farley]

Healthy and sustaining being sufficient? If i want colorful coral i notice an impact under 5, granted measuring with salifert which is ballpark color chart +/- 5ppm IMO. I think this is almost "common thought" amongst SPS keepers currently.

What would be interesting is to run it down low, dosing ammonium for a few ppm NO3 maintenance and see the impact on color/vibrance of SPS to confirm "sufficiency" at a few ppm via ammonium.

Many folks in the ammonium dosing thread are testing out the best ways to dose ammonia and how to know when it is sufficient, which I have suggested can be gauged by nitrate levels.

 

[ReeferZ1227]

Many folks in the ammonium dosing thread are testing out the best ways to dose ammonia and how to know when it is sufficient, which I have suggested can be gauged by nitrate levels.

Agree, im dosing 6 x 11mL of your bicarbonate recipe per evening.

My question was around your definition of sufficient. Healthy and stable? Consideration for color/pale?

 

[Randy Holmes-Farley]

Agree, im dosing 6 x 11mL of your bicarbonate recipe per evening.

My question was around your definition of sufficient. Healthy and stable? Consideration for color/pale?

Well, I suppose it is whatever definition you want.

 

[Gregg @ ADP]

I haven’t had time to read the entire thread, but will later. This has been something that has been discussed a lot with people like @Lasse

It’s a misconception that for algae to survive/grow/reproduce, there needs to be a supply of NO3 available for their N needs. So the idea has always been to have nitrifiers oxidize the NH3 and then that sets the table for the rest of the ecosystem.

But it is far less energetically costly to algae to simply attain their N from NH3 than NO3. To obtain N from NO3, algae needs to use two different reduction reactions utilizing two different reductase proteins. Much easier for algae to just pop off a few H atoms. This would of course require non-toxic concentrations of NH3.

I haven’t gone super deep into the weeds on this, but it would not be too difficult to set up a study comparing rate of uptake or conversion between systems with only nitrifiers and systems with algae.

 

[Dburr1014]

Unscientifically lower NO3 leads to paling SPS in my tank with a stable po4 of > .05-.1

Pale being good or bad in your opinion?

 

[East1]

Who says a few ppm of NO3 are needed? I think this should be proven, maybe by RHF's experiment.

I agree with this statement.

I've been running a number of tanks for the last 4-5 years fully automated just using dosed inputs of N and P and a full set of trace elements (using A- and K+ trace elements and all for reef for ca/mg/alk) These tanks do not run on water changes and are just topped off manually both for freshwater and replenishment of the nutrient solutions.

recently I switched from KNO3 additions for the N alongside aminos to ammonium compounds and have noticed coral health vastly improves even when NO3 tends toward zero.

I haven't achieved complete zero NO3 (I was able to detect it with a Nyos test kit as around 1ppm but I don't have a low range Hanna checker) however I reintroduced KNO3 to the N solution and made a blend because I don't feed the fish and the reduction of green and brown algaes in the tank wasn't conducive to this method and they required more supplemental feedings.

In these experiements I've used tanks of small volume (sub 100 litres) with populations of 3-8 fish, primarily damselfish and centropyrge angelfish or juvenile pomacentrus.

 

[ReeferZ1227]

Pale being good or bad in your opinion?

Unsure as far as health goes, I would think pale means less algae means less potential for energy, with a balance and inverse relationship once exceeded.

From a hobbyist perspective/valuing coral pale would be seen as less desirable.

 

[BeanAnimal]

Tell that to a generation of Zeovit Zealots....