NO3, PO4 not the enemy

[pseudorand]

Food/poop decomposes into nitrate and phosphate. These are bad when they get high. So we prevent them with filter socks and skimming and remove them with water changes and GFO. And if we do enough of that, we too can have beautiful, sps dominant reefs.

I don't buy it. There are lots of examples of old, flourishing tanks that ignore the standard advice.

What's the evidence that NO3/PO4, both necessary nutrients, are bad at high levels? Perhaps they're not directly harmful, but high levels indicate something else is missing, preventing growth and nutrient uptake. Water changes would fix that, and frequently water changes are widely thought to be effective.

But what about Lasse' report of no WC? His tank is mature and has lots of big corals. But they're not growing. At least not to the same extent we want frags to grow. Imagine a new tank full of frags. We want them to grow to maybe 10x in size. But once they have, growth must stop (or at least slow to a rate fragging can handle) or they'll be bigger than the tank.

So new tanks and mature tanks are completely separate beasts. New tanks need fast growth conditions. Slow growth conditions in mature, "full" tanks save you the trouble of fragging all the time.

So am I on to something? I've heard "there are lots of ways to be successful" many times, but I think that translates to "we don't fully understand the science yet". Perhaps this is a component of different methods to successful tanks.

 

[HuduVudu]

Everyone has different goals for their tanks.

 

[JAC-]

I like the thought and I agree that there is some support for your thoughts. Unfortunately, all I can offer is more speculation. I will say that there are many things that are helpful or needed in our and other animals bodies that are fatal in elevated concentrations so the concept of too much of a good thing is not new.
On your point of growth of frags vs established colonies, I think of a baby vs a full gown person. The baby is going to have a much lower tolerance for the same amount of a toxin than the adult, because there is a lot more adult to process the toxin and the effect is less concentrated mostly just because the adult is bigger.

Just my thoughts based on my abstract interpretations of observations, so take it with a spoon of salt.

Thanks for getting the wheels turning. I'm curious to see what our other friends have to say.

 

[Chrisv.]

Po4 literally inhibits skeletal growth. Please don't confuse random reef dudes on the internet not knowing for scientists not knowing.

https://royalsocietypublishing.org/doi/10.1098/rsos.201214

 

[JAC-]

Po4 literally inhibits skeletal growth. Please don't confuse random reef dudes on the internet not knowing for scientists not knowing.

https://royalsocietypublishing.org/doi/10.1098/rsos.201214

The article also sites higher total nitrogen inhibits growth. So a bit of a double whammy.

The article points out that the phosphorus inhibits calcium carbonate from forming, in turn the corals are not able to grow the skeleton. I believe I recall hearing that frequently before. I suppose if there was something that could cancel that out then the higher phosphate wouldn't be an issue, but hard to imagine a more diverse and established reef environment that the ocean.

 

[Chrisv.]

The article also sites higher total nitrogen inhibits growth. So a bit of a double whammy.

The article points out that the phosphorus inhibits calcium carbonate from forming, in turn the corals are not able to grow the skeleton. I believe I recall hearing that frequently before. I suppose if there was something that could cancel that out then the higher phosphate wouldn't be an issue, but hard to imagine a more diverse and established reef environment that the ocean.

I thought the results from the recent brs investigation of calcium reactor media was particularly interesting. They found that reactor media that is literally composed of wild sps skeletons has a ton of po4. I suspect that calcium phosphates and calcium carbonates are energetically close enough that even in the ultra-low phosphate of the unpolluted natural reef, phosphate is constantly at odds with calcium carbonate deposition.

 

[JAC-]

I thought the results from the recent brs investigation of calcium reactor media was particularly interesting. They found that reactor media that is literally composed of wild sps skeletons has a ton of po4. I suspect that calcium phosphates and calcium carbonates are energetically close enough that even in the ultra-low phosphate of the unpolluted natural reef, phosphate is constantly at odds with calcium carbonate deposition.

Interesting, that makes since. Going to look that up now.

Thanks for the info friend,

 

[Charlie’s Frags]

 

[BillyW]

What do you keep your other parameters at?

 

[pseudorand]

So we've got replies with scientific articles demonstrating the negative effects of NO3/PO4 and replies with beautiful corals in high-nutrient water. Neither are inconsistent with my hypothesis.

New tanks need ideal conditions to get growth. Once the tank is full, growth is inhibited, but you don't want much growth anyway.

It could also be that frequent water changes boost ??? above ocean levels, which allow corals to still thrive with high nutrients.

Water changes solve problems, I don't think that's in debate. But why they work is unclear to me.

 

[Charlie’s Frags]

What do you keep your other parameters at?

Alk 6.5-9
Ph 8.0-8.65
Par 200-500
I don’t really care about anything else

 

[Charlie’s Frags]

So we've got replies with scientific articles demonstrating the negative effects of NO3/PO4 and replies with beautiful corals in high-nutrient water. Neither are inconsistent with my hypothesis.

New tanks need ideal conditions to get growth. Once the tank is full, growth is inhibited, but you don't want much growth anyway.

It could also be that frequent water changes boost ??? above ocean levels, which allow corals to still thrive with high nutrients.

Water changes solve problems, I don't think that's in debate. But why they work is unclear to me.

I followed the sps handbook when I set up this tank. I tried gfo, nopox, biopellets, zeovit and couldn’t keep sps alive longer than a month. So I went back to my old methods from 10 years ago before there were ultra low Po4 test meters. I stopped worrying about no3/Po4

But I do try to keep agricultural runoff at a minimum

 

[Nano sapiens]

One could write a novel on this subject.

In short, yes one should not automatically assume that what works in a young system will work in an older one (a bit like apples and oranges; both fruit, yet distinctly different). And we don't yet understand all the synergies, complexities and interdependencies in our reef environments (especially not in the more complex mature ones).

Basically, we take information that applies to natural reefs and apply it to captive reefs where it looks to be appropriate to do so. This has been fruitful to a large extent, however we need to be especially skeptical when comparing two different environments when we only have scientific study results from one.

PO4 and NO3 levels are a classic case; very low on pristine oceanic natural reefs, but these same very low levels in a captive system *can* be deleterious. Corals and other animals on the natural reef typically do well under these conditions due to substantially larger amounts of prey capture (zooplankton - pelagic and especially benthic, phytoplankton, 'marine snow' detritus, etc.) than what we can provide in a captive environment. Keeping some PO4 and NO3 available in the water column is therefore especially beneficial in a young system that hasn't developed larger populations of benthic organisms/pelagic bacteria, etc. Many mature systems can run at very low water column PO4 and NO3 as nutrient availability and turnover/assimilation is much quicker than in a sparsely populated young system, so they don't stay in the water column for measurement. However, on the other end we have many mature systems with elevated levels that do well, too, which tells us something about the adaptability of reef organisms. IME, any major PO4/NO3 changes from one extreme to another should be done gradually to allow the system, and especially the coral holobiont, to successfully adjust to the change of conditions.

And then we can discuss this notion of a certain relationship between carbon, nitrogen and phosphate for optimal reef aquarium success, but then that's a whole other chapter

 

[Charlie’s Frags]

Anybody else wonder what these peer reviewed scientist’s/marine biologist’s at home 25-200g mixed reef tanks look like?

 

[Chrisv.]

Anybody else wonder what these peer reviewed scientist’s/marine biologist’s at home 25-200g mixed reef tanks look like?

You sure are smarter than those peaky scientists!

 

[Charlie’s Frags]

You sure are smarter than those peaky scientists!

Never claimed to be…..but I bet my acropora look better than theirs

 

[HuduVudu]

Reason without reality is worthless.

 

[Miami Reef]

I agree that normal ranges in a reef tank PO4: 0.08-0.12 and nitrates 5-10 is great as it encourages growth, but not to the point where algae smothers corals.

I do believe high phosphates can inhibit calcification, but how high is too high?

I don’t buy into the ULN tanks. After seeing burnt coral tips, slower growth, and dinos in my own tank.

 

[Nano sapiens]

You sure are smarter than those peaky scientists!

Never claimed to be…..but I bet my acropora look better than theirs

I think we can agree that just because a marine scientist understands a good deal about the natural reef environment, that doesn't mean he/she will automatically be a good reef keeper. A successful reef aquarist (hobbyist or marine scientist) typically has a certain set of characteristics (described as 'sensitivity', 'empathy', 'pragmatism', 'skepticism', 'sense of the artistic', etc.) as well as practical knowledge that help him/her create and maintain a thriving reef aquarium.

 

[LRT]

Thanks for reminding me to watch more Rich Ross videos I feel like I've read papers and articles totally contradicting themselves on everything being discussed here haha.
We have super nice reefs running untra low levels and levels off the charts here. Its very interesting for sure.