Why be skeptical of the need to match NSW levels of trace elements?

[Randy Holmes-Farley]

Trace elements continue to pose a dilemma for reefers who are not sure which chemical forms of which trace elements are needed at what range of concentrations for each individual organism.

We are making some small progress, but have a long way to go.

One of the conundrums that face reefers is that many reef tanks seem to do perfectly fine without measuring or dosing trace elements. Others are fine just adding one (say, iron) or a few in some random element mix made by a company that at best is trying to meet the needs of wide ranging reef tanks with a single product.

How can all of these trace elements be in an optimal range without the high degree of control that some methods using ICP and individual dosing attain?

Here's one way this all works out: the optimal range of concentration may span a vast range from very low to very high.

Taking a recent example for a single organism ( Synechococcus cyanobacteria) and a single element (zinc), these folks have shown that the cyano can adapt itself to a huge range of available zinc by having a specific uptake mechanism for it, and which it can ramp up or down as needed when supplies are lowest or highest. This organism is not a priority organism for most reefers, but there's no reason to assume that organisms we care about have not developed similar sorts of mechanisms for their own needs, and we will likely find that many trace elements can vary considerably before being too high or too low for our desired organisms, unlike certain of the tank attributes we currently focus most on (say, calcium or alkalinity).

A single sensor controls large variations in zinc quotas in a marine cyanobacterium

A single sensor controls large variations in zinc quotas in a marine cyanobacterium - Nature Chemical Biology

The zinc-sensor protein Zur in a marine cyanobacterium is distinct from those in other bacteria in structure and location of its sensory zinc site, and facilitates growth across a range of zinc concentrations via activation of a metallothionein gene.

www.nature.com

Abstract
Marine cyanobacteria are critical players in global nutrient cycles that crucially depend on trace metals in metalloenzymes, including zinc for CO2 fixation and phosphorus acquisition. How strains proliferating in the vast oligotrophic ocean gyres thrive at ultra-low zinc concentrations is currently unknown. Using Synechococcus sp. WH8102 as a model we show that its zinc-sensor protein Zur differs from all other known bacterial Zur proteins in overall structure and the location of its sensory zinc site. Uniquely, Synechococcus Zur activates metallothionein gene expression, which supports cellular zinc quotas spanning two orders of magnitude. Thus, a single zinc sensor facilitates growth across pico- to micromolar zinc concentrations with the bonus of banking this precious resource. The resultant ability to grow well at both ultra-low and excess zinc, together with overall lower zinc requirements, likely contribute to the broad ecological distribution of Synechococcus across the global oceans.

 

[CoastalTownLayabout]

I’ve always looked at this in a similar vein to the human diet. Bodybuilders, elite athletes and the wellness obsessed often spend inordinate amounts of time measuring food, mineral groups and vitamins. Others just try and eat as much fresh food as possible notwithstanding the inevitable periodic lapses.

If you want your acros to look totally ripped then all power to you but personally I’m okay with a generally healthy looking tank.

 

[taricha]

Thus, a single zinc sensor facilitates growth across pico- to micromolar zinc concentrations with the bonus of banking this precious resource.

picomolar of Zn = 10^-12 molar so like ~0.0001 ppb.
micromolar = 10^-6 so like ~100 ppb.

That's pretty ridiculous that they can grow at almost any achievable zinc concentration.

 

[jda]

I wish that we would talk about forms of elements and not just elements themselves... try and see if some forms are more useful than other, or not.

In this case, was it elemental zinc, zinc citrate, zinc acetate, zinc monomethionine or another kind? Does it matter at all?

 

[GARRIGA]

Known of the importance of trace since the 80s yet then no way to test it and no clue how to administer. I'm seeking simplicity and why for now have chosen to dose AFR plus Tropic Marin A&K although not yet sure how to supplement that then whatever is missing based on ICP. Guessing that matching NSW might not help but don't see how it will hurt. Leaning towards the Dutch method which relies on less components than Moonshiner but seeking the Trident approach to keeping a Fuge. Going to keep it flexible and most likely some bastardize hybrid. It's all good.

Testing now so I can better fine tune my approach yet hoping to have a system design that will allow future changes as the hobby advances. When I started zero nitrates was the goal and since changed yet I believe that with heavy feeding that might still be easiest to accomplish versus walking a narrow range with both phosphates and nitrates because of some study knowing the reef is absent of such measures and why that and trace I haven't closed the book on and will keep an open mind to see where it goes. In the end I'll be happy with mushrooms and coraline algae thick as baseball grass. I'll try my best watching others to glean what I can. Bunch of rocks with tangs won't make me sad, either.

 

[Dan_P]

picomolar of Zn = 10^-12 molar so like ~0.0001 ppb.
micromolar = 10^-6 so like ~100 ppb.

That's pretty ridiculous that they can grow at almost any achievable zinc concentration.

Almost as large as the apparent variation in ICP results.

 

[Randy Holmes-Farley]

I wish that we would talk about forms of elements and not just elements themselves... try and see if some forms are more useful than other, or not.

In this case, was it elemental zinc, zinc citrate, zinc acetate, zinc monomethionine or another kind? Does it matter at all?

I believe they used simple ionic zinc from zinc sulfate. No organic complexation in growth experiments.

 

[Court_Appointed_Hypeman]

Given my experience with growth of iron consuming organisms, and my rate of dosing, this makes sense.

If my same dose for a softball size chaeto that saved it from melting, is the same dose I am putting in now that its the size of a beach ball, it makes sense that it might be getting consumed based on varying degrees of availability.

 

[paintman]

Well I guess Randy just blew the Reef Moonshiners handbook out of the water. LOL!

 

[GARRIGA]

Well I guess Randy just blew the Reef Moonshiners handbook out of the water. LOL!

Why I treat keeping life more art than science being I doubt anyone has completely figured out the science but it sure helps sales when one sells science

Not implying any are purposely deceiving but we often have success, anecdotally assign that to some act we've followed then go onto to tell others and they follow it. Luckily we have Randy applying science so that we the audience can then decide how best to follow or not.

 

[Roberto Denadai]

IMHO, chasing trace elements is a waste of time and money. Just a joke for me.

The question in my head is , can I improve the tanks that I had in the past chasing trace elements???

For me, the answer is clearly no.

This is my reef 18 years ago.....without magic pills or something like that. Just food for thought

 

[Hans-Werner]

Is phosphorus a trace element or a main nutrient?

Natural concentrations frequently are as low as 3 or 6 ppb, far lower, by an order of magnitude, than iodine.

 

[Not_Erick]

IMHO, chasing trace elements is a waste of time and money. Just a joke for me.

The question in my head is , can I improve the tanks that I had in the past chasing trace elements???

For me, the answer is clearly no.

This is my reef 18 years ago.....without magic pills or something like that. Just food for thought

Gorgeous! Don’t people end up crashing tanks chasing numbers?

 

[Randy Holmes-Farley]

Is phosphorus a trace element or a main nutrient?

Natural concentrations frequently are as low as 3 or 6 ppb, far lower, by an order of magnitude, than iodine.

I wasn’t meaning to include it in these discussions, despite fitting the definition, but IMO it is a case where matching natural levels is not necessarily optimal in a reef aquarium.

 

[djf91]

I wasn’t meaning to include it in these discussions, despite fitting the definition, but IMO it is a case where matching natural levels is not necessarily optimal in a reef aquarium.

Hey @Randy Holmes-Farley, can you explain this further? Why is it different?

 

[Hans-Werner]

I have done a lot of research on trace elements in corals in the last 30 years.

Do we know "nsw levels" for coral habitats at all and if so which are the right ones?

We know the nsw levels for trace elements at different depths from crusades across the open oceans. These are not necessarily the same concentrations we find in coastal coral habitats.

We have a lot of numbers from analyses of coral skeletons and these seem to suggest trace elements concentrations in coastal habitats are varying.

We have some trace elements concentrations of water from coral habitats also, but are they the "right ones"? Trace elements concentrations in coastal habitats may vary even more than the two orders of magnitude for zinc in open ocean water from different depth. So organisms, especially if they live in coastal habitats, have to be adaptable.

 

[Randy Holmes-Farley]

Hey @Randy Holmes-Farley, can you explain this further? Why is it different?

The issues are somewhat different while the general idea of the thread, copied from the first post, is the same;

Trace elements continue to pose a dilemma for reefers who are not sure which chemical forms of which trace elements are needed at what range of concentrations for each individual organism.

Most of that statement does apply to phosphorous. P does not exist in significant amounts in a reef tank as any form except phosphate of some type, but there are dissolved organic and inorganic forms which will have different bioavailability, as well as particulate forms.

It is fairly clear to me that natural levels of inorganic orthophosphate in some ocean surface waters are too low to be good targets for a reef tank, and the results from many, many reefers show that levels above 0.01 ppm are generally better than lower levels. Thus, matching natural ocean surface water is not necessarily optimal.

 

[Randy Holmes-Farley]

So organisms, especially if they live in coastal habitats, have to be adaptable.

I don’t disagree, and that is likely part of why exactly matching any given value may not be necessary for optimal coral health.

 

[djf91]

The issues are somewhat different while the general idea of the thread, copied from the first post, is the same;

Trace elements continue to pose a dilemma for reefers who are not sure which chemical forms of which trace elements are needed at what range of concentrations for each individual organism.

Most of that statement does apply to phosphorous. P does not exist in significant amounts in a reef tank as any form except phosphate of some type, but there are dissolved organic and inorganic forms which will have different bioavailability, as well as particulate forms.

It is fairly clear to me that natural levels of inorganic orthophosphate in some ocean surface waters are too low to be good targets for a reef tank, and the results from many, many reefers show that levels above 0.01 ppm are generally better than lower levels. Thus, matching natural ocean surface water is not necessarily optimal.

I guess my question is why do these low levels of phosphate work for Acropora in the ocean but not in our aquariums? We have created a more optimal environment for Acropora than wild coral reefs?

 

[Hans-Werner]

I guess my question is why do these low levels of phosphate work for Acropora in the ocean but not in our aquariums? We have created a more optimal environment for Acropora than wild coral reefs?

If I may add my opinion: Because there are forms of phosphate, especially particulate phosphate from fish feces that snow down on corals, that are not measured by the usual water phosphate analyses.