Randy's thoughts on trace elements

[Koty]

Limiting food most certainly limits growth. It may not be the only tool, but to say that is not efficient (or does not work) is a stretch.

I would argue that it is not an efficient tool to fight or control algea growth simply from the fact that you cannot deplete them exclusively for algae and not for corals.

Do they? Th ocean is fairly stable with regard to chemistry, as far as I know. I could be wrong (ignoring natural or unnatural sources in small localization, like volcanic activity, exposed ore beds, polluted outflow, etc.)

Quoting from the article heading this thread:"2. For major ions, the concentration does not vary by location or depth in the oceans. The only significant variation in major ion concentration comes as the salinity changes. Trace elements, however, are different, and can vary considerably by location and depth. Some are surface depleted. Some are depleted deeper down. No single number, for example, can tell you the natural ocean concentration of, say, iron. If one is targeting a “natural” concentration of iron, what number would one choose? The ocean does not tell us a definitive answer."

Although it is not an experiment as n=1 (my DT) and there is no control, I found that my Cheato started growing like crazy once I started adding TM trace A and K to my three-part dosing system. I have a lot of heavily fed fish, so N and P are not too high but never 0. My take is that the Cheato was growing much slower as one of the elements was rate-limiting. GHA followed by and is way too happy in my tank. So now I have decided to stop dosing the trace elements and see if I can reduce the GHA growth. Clearly, at some point, I will start dosing the trace elements, though at a much lower concentration. My sump contains GHA, cyanobacteria, Aiptesia, and countless critters, probably because I never dipped my corals (counting on my wrasses to do their thing). Time will tell if this strategy will work. Will update.

 

[Thales]

It is certainly possible that there is some level of one or more trace elements that limits algae and not corals. Some folks have discussed this in the context of Thames/Richard Ross’ tank which has high nitrate and phosphate and no algae. I do not recall what his thoughts were in this most recently.

@Thales

The problem with the theory is that I do not know how successful we are at providing particulate foods for everything we want to keep, or even if they will all consume such foods.

I haven't seen much to make me think trying to limit anyting in a reef tank will practically help manage algae issues. Algae are so much better at life than corals, and they need so much less of the nutrients or trace elements than coral do, that I see no way to keep corals alive at nutrient levels that practically impact algal growth.

My tank has algae in the same way a wild reef has algae - it is growing all over the place all the time, but the suite of herbivores I stock keep it in check. Different herbivores can have different impacts on different algaes, and in different locations, so a suite of herbivores is needed and it isn't simply getting tang or 50.

Neither of those ideas is new, both have been a staple of marine biology forever - if you fence off an area of reef from herbivores, algae takes over that fenced off area. The opposite is also true, if you fence herbivores into an algae dominated area, the amount of algae goes down in the fenced off area. I think it is only the hobby that has promoted the idea that tweaking nutrients or trace elements based on ideas that seem not to hold up, but that do seem to make sense on first consideration.

If you dump golf course or agricultural levels of N and P on a wild reef algae will grow faster. Most of the time, reefs that go eutrophic and phase shift to algal dominance also have their herbivore populations messed up. In the Caribbean and Atlantic and Gulf, the various diadema die offs (happening since 1982) combined with systemic overfishing of parrot fish have allowed the algae to take over....it isn't just the N and P change. The idea that algae will grow slower with lower levels on N and P may be true, but reaching those levels is not healthy for corals.

If anyone is interested, a lot of this is laid out in my 2022 MACNA talk.

I hope that addressed what you were looking for Randy!

 

[BeanAnimal]

I would argue that it is not an efficient tool to fight or control algea growth simply from the fact that you cannot deplete them exclusively for algae and not for corals.

That makes no sense. Low nutrients is low algae and high nutrients feeds algae with a need for other aggressive means to keep it at bay. It’s like saying keeping sweets out of the home is not an efficient way to treat obesity. Of course it is, and if you have sweets in the home you need to work harder to negate their effect.

Quoting from the article heading this thread:"2. For major ions, the concentration does not vary by location or depth in the oceans. The only significant variation in choose? The ocean does not tell us a definitive answer."

Yes but I think you will find that coral species greatly vary by depth a location, and therefore some TE concentrations.

Although it is not an experiment as n=1

yes n=1

 

[Koty]

That makes no sense. Low nutrients is low algae and high nutrients feeds algae with a need for other aggressive means to keep it at bay. It’s like saying keeping sweets out of the home is not an efficient way to treat obesity. Of ours sir is and if you have sweets in the home you need to work harder to negate their effect.

I think you are not considering the term rate limiting factor. So, your example may be a bit off. Algae may grow fast or slow at high or low concentrations of N and P if some other factor limits them.
Also, N=1 is still > 0

 

[Koty]

I haven't seen much to make me think trying to limit anyting in a reef tank will practically help manage algae issues. Algae are so much better at life than corals, and they need so much less of the nutrients or trace elements than coral do, that I see no way to keep corals alive at nutrient levels that practically impact algal growth.

My tank has algae in the same way a wild reef has algae - it is growing all over the place all the time, but the suite of herbivores I stock keep it in check. Different herbivores can have different impacts on different algaes, and in different locations, so a suite of herbivores is needed and it isn't simply getting tang or 50.

Neither of those ideas is new, both have been a staple of marine biology forever - if you fence off an area of reef from herbivores, algae takes over that fenced off area. The opposite is also true, if you fence herbivores into an algae dominated area, the amount of algae goes down in the fenced off area. I think it is only the hobby that has promoted the idea that tweaking nutrients or trace elements based on ideas that seem not to hold up, but that do seem to make sense on first consideration.

If you dump golf course or agricultural levels of N and P on a wild reef algae will grow faster. Most of the time, reefs that go eutrophic and phase shift to algal dominance also have their herbivore populations messed up. In the Caribbean and Atlantic and Gulf, the various diadema die offs (happening since 1982) combined with systemic overfishing of parrot fish have allowed the algae to take over....it isn't just the N and P change. The idea that algae will grow slower with lower levels on N and P may be true, but reaching those levels is not healthy for corals.

If anyone is interested, a lot of this is laid out in my 2022 MACNA talk.

I hope that addressed what you were looking for Randy!

All I was trying to point to is the fact that however efficient algae may be, its only source is the water column, while creatures that eat may complement what is missing in the water column from their food.
Where I live, herbivores that are not fish are banned. I did not dip my corals, so I got some as hitchhikers. These guys, however, eat algae but keep the nutrients in the tank, so they are half of a solution.

 

[jda]

Nothing has changed at my house in a few decades... no3 at about 0.10 and po4 at 1-3 ppb and I would have algae take over my tank without consumers - for me that is urchins, snails, some manual removal and also an occasional rabbitfish before they grow too big. I have yet to see a tank be able to lower waste products like no3 and po4 to the point where algae is even really limited much without harming the corals more.

The only exception to this is when I want to grow algae like chaeto - I can limit this growth without harming corals by not dosing iron. This does not work on turf algae, though.

Those ag levels of N and P also keep corals from calcifying, so this helps algae too.

 

[Thales]

All I was trying to point to is the fact that however efficient algae may be, its only source is the water column, while creatures that eat may complement what is missing in the water column from their food.

I am not following. Algae can also take up nutrients locally where they are attached to substrates

Where I live, herbivores that are not fish are banned. I did not dip my corals, so I got some as hitchhikers. These guys, however, eat algae but keep the nutrients in the tank, so they are half of a solution.

I am not following

 

[BeanAnimal]

I think you are not considering the term rate limiting factor. So, your example may be a bit off. Algae may grow fast or slow at high or low concentrations of N and P if some other factor limits them.
Also, N=1 is still > 0

No, I am just not conflating data to conclude that keeping low P and N is not an efficient means of keeping nuisance algae in check. Yes there can be other limiting factors, but an excess of food is an ex excess of food. And to your point, you want to identify certain traces to limit to reduce nuisance algae, but not affect coral. I get it, but again, zooxanthellae are algae, so I think you may find that the same traces likely apply.

 

[Randy Holmes-Farley]

I haven't seen much to make me think trying to limit anyting in a reef tank will practically help manage algae issues. Algae are so much better at life than corals, and they need so much less of the nutrients or trace elements than coral do, that I see no way to keep corals alive at nutrient levels that practically impact algal growth.

My tank has algae in the same way a wild reef has algae - it is growing all over the place all the time, but the suite of herbivores I stock keep it in check. Different herbivores can have different impacts on different algaes, and in different locations, so a suite of herbivores is needed and it isn't simply getting tang or 50.

Neither of those ideas is new, both have been a staple of marine biology forever - if you fence off an area of reef from herbivores, algae takes over that fenced off area. The opposite is also true, if you fence herbivores into an algae dominated area, the amount of algae goes down in the fenced off area. I think it is only the hobby that has promoted the idea that tweaking nutrients or trace elements based on ideas that seem not to hold up, but that do seem to make sense on first consideration.

If you dump golf course or agricultural levels of N and P on a wild reef algae will grow faster. Most of the time, reefs that go eutrophic and phase shift to algal dominance also have their herbivore populations messed up. In the Caribbean and Atlantic and Gulf, the various diadema die offs (happening since 1982) combined with systemic overfishing of parrot fish have allowed the algae to take over....it isn't just the N and P change. The idea that algae will grow slower with lower levels on N and P may be true, but reaching those levels is not healthy for corals.

If anyone is interested, a lot of this is laid out in my 2022 MACNA talk.

I hope that addressed what you were looking for Randy!

Perfect. Thank you for chiming in.

 

[BeanAnimal]

I haven't seen much to make me think trying to limit anyting in a reef tank will practically help manage algae issues. Algae are so much better at life than corals, and they need so much less of the nutrients or trace elements than coral do, that I see no way to keep corals alive at nutrient levels that practically impact algal growth.

I do tend to disagree with part of this. Yes, the algae appears to be much better at consumption and survival, but I still firmly believe that the more excess in food, the more nuisance the algae becomes. I don't thinking limiting N and P solves the problem, but I think it is a key element to the solving the problem.

My tank has algae in the same way a wild reef has algae - it is growing all over the place all the time,

I think that this is a very key difference between our captive systems and a wild reef. The wild reef has exponentially more grazers than we could ever dream of keeping. They may not be concentrated in one spot, but they cover enormous area daily. Watching a school of fish graze, it becomes obvious why there are no large outcrops of algae. It is there, but they keep it mowed down.

In any case, interesting discussion, but I don't want to divert too far from the trace element aspect of this thread.

 

[Thales]

I do tend to disagree with part of this. Yes, the algae appears to be much better at consumption and survival, but I still firmly believe that the more excess in food, the more nuisance the algae becomes. I don't thinking limiting N and P solves the problem, but I think it is a key element to the solving the problem.

I don't think it is key, and don't think that it has been shown to be key. It's like the study on phosphae and calcification - it was like 8% slower calcification at higher levels (for those corals and those levels). 8% doesn't make the juice worth the squeeze for me, though it might for someone trying to make things grow as fast as possible at scale.
I don't limit N and P much at all, and I don't have the problem.

I think that this is a very key difference between our captive systems and a wild reef. The wild reef has exponentially more grazers than we could ever dream of keeping. They may not be concentrated in one spot, but they cover enormous area daily. Watching a school of fish graze, it becomes obvious why there are no large outcrops of algae. It is there, but they keep it mowed down.

There are also a billion other grazers that aren't fish that don't cover that much reef over the day. I don't see it as much of a problem to keep tweaking the CUC as needed to keep up on the algae. Seems like less of a bother to do that than to add all the infrastructure, time, and money needed to tweak n and p (which I haven't seen be much of a help). YMMV.

In any case, interesting discussion, but I don't want to divert too far from the trace element aspect of this thread.

Understood. Always fun talking to you.

 

[Thales]

Perfect. Thank you for chiming in.

At your service!

 

[Koty]

No, I am just not conflating data to conclude that keeping low P and N is not an efficient means of keeping nuisance algae in check. Yes there can be other limiting factors, but an excess of food is an ex excess of food. And to your point, you want to identify certain traces to limit to reduce nuisance algae, but not affect coral. I get it, but again, zooxanthellae are algae, so I think you may find that the same traces likely apply.

Yes zooxanthella are algea indeed but live inside a coral that may get its trace elements from food and not from the water column

 

[BeanAnimal]

Yes zooxanthella are algea indeed but live inside a coral that may get its trace elements from food and not from the water column

But wait - then can't we limit N and P in the "water column" to starve the nuisance algae and just target feed the coral?

But wait - don't the corals feed from the water column?

Choose one, choose both, but your logic doesn't carry... I am going to kindly see my way out of the conversation. I think it is going to go in circles and it is rather tangential to this thread.

 

[Hans-Werner]

That all said, aside from possibly wasting time and money, there is certainly no drawback to supplementing lithium, barium and rubidium to natural levels.

I wouldn't stress the argument of wasting time and money overly with barium (ca. 0.1 µM or ca. 14 µg/l), at least not when talking about a commercial scale.

With rubidium and lithium in salt mixes it is a bit different:

On iodine:

I consider it a minor element, but some definitions do consider it a trace element. But that difference is just semantic.

The concentration of iodine in seawater is 0.2 - 0.5 µM, average 0.4 µM (50 µg/l), the concentration of rubidium in seawater is 1.4 µM (120 µg/l) and of lithium it is 25 µM (172.5 µg/l) (data from Millero, Chemical Oceanography).

Nevertheless I think there are no good arguments against including and maintaining natural concentrations, and there are presumptions that these elements discussed here at least have beneficial effects. Hard to imagine any benefit leaving them away completely except saving money.

 

[Hans-Werner]

But wait - then can't we limit N and P in the "water column" to starve the nuisance algae and just target feed the coral?

Yes, at the same concentrations and in the same water corals may be phosphate limited while algae may be nitrogen limited. It is due to different demand and different uptake systems.

 

[Lasse]

phosphate limited while algae may be nitrogen limited.

Yes - and IMO many microalgae can´t use NO3 as N source but are able to use N in the form of NH4/NH3. To me - it seems that zooxanthellae´s are able to use NO3 as N source.

Sincerely Lasse

 

[Doctorgori]

has anyone noticed algae grows faster on new/dry rock as opposed to established/ coralline rock?
…yes nutrient limitation is key but also is habitat denial/ displacement …
..it’s harder for algae to grow/ attach if something is already there

 

[Randy Holmes-Farley]

I wouldn't stress the argument of wasting time and money overly with barium (ca. 0.1 µM or ca. 14 µg/l), at least not when talking about a commercial scale.

With rubidium and lithium in salt mixes it is a bit different:

On iodine:

The concentration of iodine in seawater is 0.2 - 0.5 µM, average 0.4 µM (50 µg/l), the concentration of rubidium in seawater is 1.4 µM (120 µg/l) and of lithium it is 25 µM (172.5 µg/l) (data from Millero, Chemical Oceanography).

Nevertheless I think there are no good arguments against including and maintaining natural concentrations, and there are presumptions that these elements discussed here at least have beneficial effects. Hard to imagine any benefit leaving them away completely except saving money.

I wasn't so much thinking about a commercial supplement or salt mix containing multiple ions (some of which are clearly useful) as a person getting an ICP result for barium or rubidium that is low, and then looking to buy a supplement specific for it and then trying to work out a daily dose that will match demand. That is required in some newly popular methods such as reef moonshine.

 

[Lasse]

About Rubidium

Sincerely Lasse