Need Your Thoughts on Coral Coloration

[Stigigemla]

If you are going to do experiments with iron i would like to see if there is a difference depending on how we add it. Plain iron chloride, complex with citric acid or EDTA complex.
I believe most of the iron we add will precipitate with phosphate but maybe there is a difference depending of complex type. Precipiating time depending on phosphate level in the tank?

And of course it would be interesting to see how dosing period will affect. Several doses a day, one or just one time in a week?

I have customers claiming it is enough to have GFO with some flow through it to have a constant value high enough (but unmeasureable) to support our corals. Is that true even when pH goes up to 8.3 or higher?

I believe just iron can keep you occupied for a few years from now.

 

[Dana Riddle]

Red Sea makes a specific and incredibly high iron recommendation. I’ve sometimes wondered if it was that high just to be detectable with their kit. [emoji23]

Thanks Randy! I'll look for their recommendation. I seem to recall Red Sea lists peridinin as a chromoprotein. Technically, they are correct, but that accessory photopigment isn't responsible for coloration in the sense I'm referring to. Probably goes back to bad info posted on the internet back in the late 90's.

 

[Dana Riddle]

If you are going to do experiments with iron i would like to see if there is a difference depending on how we add it. Plain iron chloride, complex with citric acid or EDTA complex.
I believe most of the iron we add will precipitate with phosphate but maybe there is a difference depending of complex type. Precipiating time depending on phosphate level in the tank?

And of course it would be interesting to see how dosing period will affect. Several doses a day, one or just one time in a week?

I have customers claiming it is enough to have GFO with some flow through it to have a constant value high enough (but unmeasureable) to support our corals. Is that true even when pH goes up to 8.3 or higher?

I believe just iron can keep you occupied for a few years from now.

LOL. You are correct, just researching the effects of pH on coloration has taken weeks.

 

[Peppe]

Dana, I have never understood the question oligo .. I have a reef full sps but I can not pull out certain colors .. I use balling light fauna marin where elements are already contained trace, but I do not use the color element green, blue, purple . in your opinion to improve some colors what should I put in order to evaluate any possible effects? furthermore, if zinc is better not to add it, why is it present in many compounds to add oligo? here are some photos of my reef

 

[Peppe]

 

[jsker]

i'm an aquaforest guy.i use the component 1-2-3 as well as the micro e trace elements and the amino mix.i have gotten growth and coloration in corals ive had for 10 plus years like never before.it's only been 3 months but the change has been incredible to say the least.

I am there with you.

 

[Randy Holmes-Farley Verified Community Expert]

If you are going to do experiments with iron i would like to see if there is a difference depending on how we add it. Plain iron chloride, complex with citric acid or EDTA complex.
I believe most of the iron we add will precipitate with phosphate but maybe there is a difference depending of complex type. Precipiating time depending on phosphate level in the tank?

And of course it would be interesting to see how dosing period will affect. Several doses a day, one or just one time in a week?

I have customers claiming it is enough to have GFO with some flow through it to have a constant value high enough (but unmeasureable) to support our corals. Is that true even when pH goes up to 8.3 or higher?

I believe just iron can keep you occupied for a few years from now.

While I know that some folks dose iron to precipitate phosphate, have you ever seen a mass balance study that shows how much iron precipitates how much phosphate in a reef aquarium, vs what is traditionally discussed by scientists to be happening in the ocean, which is precipitation of iron oxide/hydroxide?

 

[mcarroll]

I'm especially interested in hearing of iron concentrations since it is easily tested for in seawater.

This seems contrary to my reality...Randy has great ideas about iron all the time but it seems like it must be virtually untestable as nobody seems to know their irin levels....even Triton doesn't report Iron.

What's a good option for Iron testing at home?

@Randy Holmes-Farley you're known for the "don't add what you can't test philosophy" – did you test for Iron while you were dosing it? How? Seems like I remember No but I could be misremembering.

 

[Randy Holmes-Farley Verified Community Expert]

This seems contrary to my reality...Randy has great ideas about iron all the time but it seems like it must be virtually untestable as nobody seems to know their irin levels....even Triton doesn't report Iron.

What's a good option for Iron testing at home?

@Randy Holmes-Farley you're known for the "don't add what you can't test philosophy" – did you test for Iron while you were dosing it? How? Seems like I remember No but I could be misremembering.

It is only testable if you add what I consider to be big doses, or right after dosing.

My Triton Testing Results
http://www.reefedition.com/my-triton-testing-results-by-randy-holmes-farley/

Iron (Fe). The natural iron level varies a lot with depth, but surface seawater may have only 0.006 µg/L. The Triton LOD = 0.3 µg/L. I dose iron, and when I dose it I boost iron to roughly 1-2 µg/L, which would be detectable. This sample was taken more than a week after the last iron dosing, and none was detected as it gets depleted in the meanwhile. I’ve not yet seen a Triton test result for a real aquarium sample that had detectable iron, but that doesn’t mean these tanks are necessarily deficient. Iron is also a case where the form is critical, and ICP cannot distinguish form. Binding to organic matter, for example, can alter the bioavailability of iron.

 

[hart24601]

Here are my experiences, 1st on nutrients - despite the swing of people dosing phosphates, my colors were by far the best when hanna was 0ppb, in fact I could tell in mari colonies when my phosphates would start rising as the coral would brown out very fast, I can't remember what range, but it was around .03ppm. That being said I fed that tank a great deal, so there was always phosphate in the water even if not detectable. I found nitrates had to be present, just a hint of color on salifert test. I didn't notice any greater color with nitrates higher than that.

I also noticed a great impact of colors on aquacultred acros and light intensity. I personally noticed shifts around 300 PAR, such as strawberry shortcake developing more colors other than green and the 300-500 range was the "sweet spot" with higher PAR or even at the higher end of that range not really changing colors.

 

[Reefin Dude]

it is important to note the difference between inorganic and organic P and N with corals. i feed a ton, supplying the corals with lots of organic N and P, and make sure there is as little inorganic N and P available (what is testable).

G~

 

[Dana Riddle]

I’m not a chemistry major, and I am certainly open to be enlightened, but this is my understanding of iron testing (using Hach methods, which are useful in testing seawater):

Total Iron – Ferrous Iron = Ferric iron

Total Iron (FerroVer chemistry, 1,10 phenanthroline method): Digestion (boiling acidified sample) is recommended for EPA reporting purposes. Reacts with all soluble iron and most insoluble forms of iron. Detection limit with my instrument (DR890 colorimeter) is 0.03 mg/L.

Ferrous Iron (1,10 phenanthroline method): Reacts only with ferrous (not ferric iron.) Detection limit with my instrument (DR890 colorimeter) is 0.03 mg/L.

As for organics in a reef aquarium, I’ve performed several Biochemical Oxygen Demand (BOD5) tests over the years and have never seen a recommended drop of 2 mg/L O2 over the course of the 5-day test. Results have been much less, ~0.02 mg/L. For comparative purposes, domestic wastewater has a BOD of about 250 mg/L (the engineering standard used during design) while the BOD limit of the treated effluent is usually 30 mg/L (although it is usually much less.) The EPA allows Total Organic Carbon (TOC) to be reported in lieu of BOD if correlations of the two tests have been established.

Finally, I’ve also performed Total Phosphorus and Total Nitrogen tests on reef aquarium water (although dilutions will be necessary to avoid interferences and digestions are required.) I’ll have to find the notebook for that period…

But to get back on track, fluorescence of the wild-type DsRed protein (isolated from the false coral Discosoma) is enhanced when exposed to iron. I’m getting some very interesting reports privately and am in discussions. Will report when finalized.

 

[Randy Holmes-Farley Verified Community Expert]

Ferrous Iron (1,10 phenanthroline method): Reacts only with ferrous (not ferric iron.) Detection limit with my instrument (DR890 colorimeter) is 0.03 mg/L.
.

That would be well above the amount I dose (1-2 ug/L), so you wouldn't detect my dose.

 

[Dana Riddle]

That would be well above the amount I dose (1-2 ug/L), so you wouldn't detect my dose.

Thanks again! If my poor memory serves me, the Hanna Checker for iron would report ferrous. It would be interesting to see some reports of iron concentrations along with these observed color shifts, if possible.

 

[thewasho]

Beautiful - thank you! Is there a link that describes these Aussie supplements - I'd like to take a look. Amino acids need a close look - certainly a nitrogen source is needed for coral, anemones, etc. to make the colorful proteins. I tested some AA supplements a few years ago, and found a couple of things, including concentrations can vary wildly, but, nore importantly, IMO, that the amino acids are apparently quickly degraded by bacteria. But that doesn't need the nitrogen disappears by any means - it is incorporated into bacteria tissues, and many corals feed to bacteria (or protozoa that feed on bacteria.)

Hi Dana,
Their coral farm website is http://sustainablereefs.com.au and their Supplement range is http://www.coralessentials.com.au

 

[Stigigemla]

Maybe it looked as if i know a lot of iron in aquariums but i dont. I am just in the stage of learning what i dont know.
The word bioavailability struck me. Is it possible that a complex binder like citric acid or edta make it easier for coral or algae to take up iron?
Or is a constant addition of iron likely better?

 

[Servillius]

Yes, especially iron additions. There are a number of claims that this element influences coloration, and Phil Dorr claims iron supplementation can prevent bleaching. I'm especially interested in hearing of iron concentrations since it is easily tested for in seawater. Yet, I haven't heard of any supplement maker making specific recommendations for iron concentrations. I'm convinced that strontium incorporation into coral skeletons is a 'mistake' as Sr is so similar to calcium but it has been suggested (not by me) that it could be a 'tonic' - but forget that - I don't want to hijack my own thread.

I understand the problem with iron being that it can’t really easily be doser sufficiently to maintain a stable equilibrium. Algae slurps up as much as you can throw at it. Trying to overwhelm the algae then keeping a fractional amount in solution is beyond our capabilities.

Edit: I see I’m late to the party and many dollars short given the resources you have on hand. Left here for historic purposes.

 

[TexasTodd]

Check out post 62 on this thread
https://www.reef2reef.com/threads/lets-see-your-t5-sps-tanks.135858/page-4
Todd

 

[Dana Riddle]

Here are my experiences, 1st on nutrients - despite the swing of people dosing phosphates, my colors were by far the best when hanna was 0ppb, in fact I could tell in mari colonies when my phosphates would start rising as the coral would brown out very fast, I can't remember what range, but it was around .03ppm. That being said I fed that tank a great deal, so there was always phosphate in the water even if not detectable. I found nitrates had to be present, just a hint of color on salifert test. I didn't notice any greater color with nitrates higher than that.

I also noticed a great impact of colors on aquacultred acros and light intensity. I personally noticed shifts around 300 PAR, such as strawberry shortcake developing more colors other than green and the 300-500 range was the "sweet spot" with higher PAR or even at the higher end of that range not really changing colors.

Your recommendations on lighting seem spot on! Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

Maybe it looked as if i know a lot of iron in aquariums but i dont. I am just in the stage of learning what i dont know.
The word bioavailability struck me. Is it possible that a complex binder like citric acid or edta make it easier for coral or algae to take up iron?
Or is a constant addition of iron likely better?

Easier or harder. My DIY is ferrous gluconate (from Fergon tablets at a drug store).

Here's a copy and paste from another thread:

The ways that trace elements exist in reef tanks, and the way they are taken up are very complex and poorly understood. Even in the ocean these things are not always well known, despite being studied.

I thought these quotes from a paper I was reading might be of interest:

The chemical speciation of iron in the north-east Atlantic Ocean
https://www.sciencedirect.com/science/article/pii/S0967063706000161

"There is still uncertainty about which form(s) of iron (organically complexed Fe(III), inorganic Fe(III), or Fe(II)) is bioavailable.

Recent work indicates that the bioavailable iron may well be inorganic Fe(III) taken up in a reductive process. Counter intuititively the concentration of such Fe(III) can be enhanced by siderophores , facilitating photochemical reduction of Fe(III) to transient Fe(II), with a subsequent re-oxidation to fresh Fe(III).

In this study, total dissolved iron averaged 0.79 nM .... the iron was 99% organically complexed, leaving a calculated inorganic Fe(III) concentration of 10.476 pM

The presence of Fe(II) shows that these waters are not at thermodynamic equilibrium. The concentration of Fe(II) was greater than that of inorganic Fe(III), indicating that this transient Fe(II) greatly changes the chemical speciation of iron."