My Collected Thoughts on N and P Dosing

[jda]

I have not been a fan of either for a while, but it was more of a hunch than totally science based. I have never had any issues with low, but detectable building blocks. However, after some time, reading and some research, I am now convinced with some science that both are a bad idea.

I just want to type this once and link to it in the future, so this is why I am starting the thread. My apologies to those who do not care.

Nitrate dosing:
Most corals prefer ammonia and ammonium to get their nitrogen. Single cell algae can do this too. Nitrate can be used, but it takes more energy and is not the preferred method. If ammonia is still in good supply, then adding extra nitrate will not do anything from what I can tell since the coral can meet their need with nh3 and nh4.

Phosphate dosing:
Dosing phosphate will mostly just get bound to the aragonite and not really get to the corals. Of course, if you add enough, then there can be some excess in the water. I fear that people will one day have to fight phosphate issues from when their rock was binding up phosphates at an elevated level.

I am not saying that people need to keep both very low. I not saying that people need to chase numbers. I am just saying that dosing is probably not a good way to help your coral if you feel they need elevated levels of building blocks... the age old adage to "just feed more" might be the way to go. Heck, ammonia dosing might be even better than dosing nitrate, but we can table this for another day.

/tldr

 

[Flippers4pups]

@jda, do you have any white papers explaining this? My experience has been strictly anecdotal from my corals response, growth and health from dosing N03 and P04. In each case, there has been positive reaction, especially in coloration and growth.

 

[jda]

No. Just a collection of other science and posts and stuff. The current thread about algae and ammonia got my juices flowing again about ammonia and coral, which is where I finished my reading about corals getting nitrogen from ammonia. Lasse has some great stuff on the end of that thread about ammonia/ammonium usage by single cell stuff and corals. You all have probably seen me post a lot about, and my experiments with, aragonite binding phosphate.

I have counseled a lot of locals to stop dosing N and P and see if anything changes and none of them can tell a difference yet. Slowly. They all did up their feedings.

 

[bubbaque]

I agree with you jda. My tank has ran near 0 no3 and po4 for most of my tanks life and I do not have pale colors or slow growth. I think those who do truly need to feed more to fix the issue. The extra food will make your fish and corals happy anyways.

 

[MTBake]

Like @Flippers4pups, I've also noticed positive results from dosing a little n and p. Just enough to get detectable levels. I'm hoping that a larger fish population will help me taper away from dosing in the near future. Time will tell.

 

[Gablami]

Yes. I’ve dosed nitrate in the past and have stopped. In addition to feeding more, seems like there is always room to decrease export mechanisms (reduce fuge lighting, take the skimmer cup off, etc). I stopped aminos too, but I could support that more than dosing straight nitrate and/or phosphate.

I would add though, that I don’t see any harm to it either.

 

[SaracensRugby]

@jda, what are your thoughts on the fact that nuisance things like cyano and Dino’s tend to show up in environments where there are low to undetectable N and P? Don’t certain algae’s/bacteria thrive at different points, so if someone has very low levels they are more likely to see these pop up? This seems to be the case in my situation, so I just started dosing Nitrate in an effort to get N between 3-5ppm.

And I feed frozen 1-2 times a day, algae for my grazers, and pellets 1 time a day. I guess I could reduce my refugium lighting period even more than I have already. I also have a Triton style sump, so all of the detritus that goes into the sump is creating a mud in there.

 

[jda]

For me, most algae issues are consumer based - not enough consumers. Astreas and Pincushions from Florida keep my tanks spotless and the urchins really help with the coralline. You are right, though... even with very low N and P, algae would overrun my tank if I did not have the consumers.

Cyano and dinos that are most common (there are a million kinds, well... a lot anyway) are poisoned with higher levels of N and P. This does not mean that you have to have dinos or cyanos with low levels of either.

Again, I am not saying that you have to have low levels, only that what you think that you are doing when you dose might not actually be helping the way that you think. However, if the goal is to poison cyano or dinos, then dosing on the back end is probably just fine.

 

[Backreefing]

Hello JDA I have read several of your posts and find your on point maybe everytime.
I agree with you opinions on N and P , but in a nutshell just add some fish and SPS is happy . Sorry for over simplifying it .
As far as cyano goes I’m onto easy natural ways to get it gone , at least for me .

 

[DarkSky]

I dose NO3 and have dosed PO4 in the past to get to detectable levels. Once I'm there, things seem to stay at detectable levels and I don't need to continue.

 

[SaracensRugby]

It’s interesting the word you used @jda, “poison” the Dino’s and cyano. Assuming that was on purpose, is that whats happening to them at detectable levels of N (3-5ppm) and P?

Its funny, I had a 60 cube with filter socks in my sump and couldn’t get detectable levels. Now I have a 127, 160 gallons total water volume, and the same “issue”. I assumed, possibly incorrectly, that a buildup up detritus in my triton sump (not being removed every couple days by a filter sock) would help add to the levels of N and P. But in this case it made no difference. I have 11 fish in this tank, so certainly not lightly stocked.

 

[Flippers4pups]

It’s interesting the word you used @jda, “poison” the Dino’s and cyano. Assuming that was on purpose, is that whats happening to them at detectable levels of N (3-5ppm) and P?

Its funny, I had a 60 cube with filter socks in my sump and couldn’t get detectable levels. Now I have a 127, 160 gallons total water volume, and the same “issue”. I assumed, possibly incorrectly, that a buildup up detritus in my triton sump (not being removed every couple days by a filter sock) would help add to the levels of N and P. But in this case it made no difference. I have 11 fish in this tank, so certainly not lightly stocked.

Not every tank is the same. Lightly stocked with corals, young tank as opposed to heavily stocked, mature tank. Mature coral tanks can handle more N03 and P04 due to uptake. Young tanks, young corals not so much.

I did at the beginning dose N03 to get to 5-10ppm and also dosed P04 to get 0.02. Now almost 4 years later, my tank can handle higher levels of N03 and P04. Been stable at 30-40 ppm N03 and 0.1 P04 now for a year. There was a time my P04 bottomed out to 0 and my corals across the board paled considerably. Dosed P04 up to 0.02 and they colored back up over a couple weeks time.

 

[jda]

Every living thing needs N and P to repair tissue and build new tissue - the building blocks of life. There is also a level where too much N and P will limit growth. Then, there is also a level where too much N and P will cause death. With too little of either, growth can be limited, but this does not usually cause death. This level is different for every organism.

In every ecosystem that I have read about, there is no difference in having a small surplus to drive the equilibrium forward and having a larger surplus - neither are growth limiting.

 

[Flippers4pups]

Every living thing needs N and P to repair tissue and build new tissue - the building blocks of life. There is also a level where too much N and P will limit growth. Then, there is also a level where too much N and P will cause death. With too little of either, growth can be limited, but this does not usually cause death. This level is different for every organism.

In every ecosystem that I have read about, there is no difference in having a small surplus to drive the equilibrium forward and having a larger surplus - neither are growth limiting.

Everything equal, I truly believe that it's a supply and demand situation regarding N03 and P04. I was of the old school teaching that N03 and P04 was very bad and needed to be both at 0. My current system taught me otherwise.

Not everyone can have this situation as I stated in my previous post. The problem is when new reefers with very young tanks see the Sanjay and Richard Ross tanks of the world with N03 at 40 -50 ppm and P04 1.0 and think they can emulate these conditions and go chasing numbers. Are their tanks healthy, colorful and grow coral at a insane rate, yes but it can't be done with everyone's tank.

 

[jda]

Have you checked in on either of those tanks lately? Ross is working his numbers back down and I heard some disturbing rumors about Joshi tank (unverified).

I have had a tank since 1992 and I have never heard of anybody wanting to truly hit zero N and P - I wonder if this is hyperbole or misunderstanding. People strove for "clear" on the very unreliable and hard-to-read N test kit, and eventually with with phosphate (which did not come along until later). Even the ocean does not have zero - it has a very small surplus, just like what the pros advocated for, even back then.

Truly getting to zero was never really a problem until people started to use media and chemicals. There is no way to truly get to zero with natural methods since they start to limit growth as you get near (to protect themselves). Natural stuff will always leave a trace of surplus.

Again, I am not saying that anybody has to have low numbers, or even debating the merit of doing so, only that dosing nitrate probably did not get to the corals since they were using ammonia/ammonium... and that you tank could still probably be where it is at now without dosing phosphate since it most likely just got bound by the aragonite. All that ended up happening was higher N number on a test kit and more P in the rocks.

 

[Flippers4pups]

Have you checked in on either of those tanks lately? Ross is working his numbers back down and I heard some disturbing rumors about Joshi tank (unverified).

I have had a tank since 1992 and I have never heard of anybody wanting to truly hit zero N and P - I wonder if this is hyperbole or misunderstanding. People strove for "clear" on the very unreliable and hard-to-read N test kit, and eventually with with phosphate (which did not come along until later). Even the ocean does not have zero - it has a very small surplus, just like what the pros advocated for, even back then.

Truly getting to zero was never really a problem until people started to use media and chemicals. There is no way to truly get to zero with natural methods since they start to limit growth as you get near (to protect themselves). Natural stuff will always leave a trace of surplus.

Again, I am not saying that anybody has to have low numbers, or even debating the merit of doing so, only that dosing nitrate probably did not get to the corals since they were using ammonia/ammonium... and that you tank could still probably be where it is at now without dosing phosphate since it most likely just got bound by the aragonite. All that ended up happening was higher N number on a test kit and more P in the rocks.

I agree that P04 does lock up in aragonite. Sand and rock, but it will equalize with the water collum. (Dry rock leaching P04 into water collum is a common occurrence, until it hits equilibrium with the water collum.)

Though the red field ratio doesn't truly translate into this discussion, it seems to lean towards if N03 is higher than P04, nuisance algaes tend to trend down.

I know that I received a post from Mike Paletta that they were at Sanjays and shot some more video. No mention for problems. This was yesterday.

No new news on Richards tank. I'll shoot him a message and see if he responds.

 

[SaracensRugby]

Great conversations in this thread.

@jda, you saying that dosing nitrate may not be getting to the corals. But some anecdotal evidence presented (taken with a grain of salt that every tank is different) says that there is an impact somewhere in the chemistry tree which is having a positive effect to the corals. So what is happening to the N that people are dosing? Being taken up by macroalgae, bacteria in the rocks, etc., thereby leaving more ammonia to be taken up by the corals? I am not even sure if that is possible chemistry wise but just thinking out loud. In effect dosing N when it is very low somehow levels the playing field and frees up “something”, maybe ammonia, for the corals to consume, which otherwise they were having to compete for and were “losing out” to other things in our tanks?

 

[dragon99]

I agree with you in situations where N and P are somewhat balanced. This research shows what can happen with just low PO4 though.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5441187/

There are definitely situations where dosing one of the two is beneficial. It's not a cure all, but shouldn't be completely dismissed as ineffective. For instance, I personally have been fighting low PO4 in my tank for a couple of years. I resisted dosing because it just didn't seem like the right answer. However, after 2 months now of dosing PO4 I can definitely say it is making a positive improvement. I realize that most is being bound of by rock and sand, but having near zero PO4 with my NO3 ~20ppm hadn't been working and feeding more wasn't the answer.

 

[jda]

I think that most N gets gobbled up by anoxic bacteria that turn it into nitrogen gas - fuges (algae and sponges) and corals also consume some as a temp store. This is not as easy in some of the modern tanks without sand and with dry rock that can take years to be able to effectively handle nitrate. Still, there are places in every tank that can do this to a degree. With my 16 square feet of 3" sandbed, any amount of N that I could add (within reason) would just increase the population of the bacteria to where there was quickly, again, just a trace.

Again, I am not wanting to argue the merits of having certain levels of N and P... as everybody knows, each tank is different. Fore example, Flipper's 30-40 nitrate is totally good in his mixed reef, but would be death to most of my smooth skinned acropora, but about half of my acropora would be OK.

 

[Flippers4pups]

I think that most N gets gobbled up by anoxic bacteria that turn it into nitrogen gas - fuges (algae and sponges) and corals also consume some as a temp store. This is not as easy in some of the modern tanks without sand and with dry rock that can take years to be able to effectively handle nitrate. Still, there are places in every tank that can do this to a degree. With my 16 square feet of 3" sandbed, any amount of N that I could add (within reason) would just increase the population of the bacteria to where there was quickly, again, just a trace.

Again, I am not wanting to argue the merits of having certain levels of N and P... as everybody knows, each tank is different. Fore example, Flipper's 30-40 nitrate is totally good in his mixed reef, but would be death to most of my smooth skinned acropora, but about half of my acropora would be OK.

My Cali tort, purple monster.... All doing very well. Abet I don't have any smooth skinned acros, but bets placed just about any acro at this point, once acclimated would do well. We'll see as I plan on a tank reset in a month. Acropora are on the menu! Lol