What forms of iron are bioavailable?

[taricha]

Along these lines, I have tried to instill in some folks the caution that oxidizers like Lugols or hydrogen peroxide or reducers like vitamin C, may be altering the bioavailability of trace elements, so when folks observe effects, it may not be due to iodine supplementation or the direct effects of these additives on things like dinos.

dang. I need to re-read the ORP and double-check which of my additives fall in this category. Iodide, and what else....

 

[taricha]

Yes provided I can also increase other biodiversity through increased p an n to out compete the Dino’s. Hoping uv adds the extra needed to check the extra growth.

So add iron to suppress the toxin while using the usual Dino killing process we are following from the other thread to out compete.

That's very cool that the diatoms respond to Fe limitation by releasing toxin, and the toxin helps alleviate the limitation (while also detoxifying Cu)
I have no idea if this'll work or not.
But if I were to make an argument for why it may not likely work, it would go like this.
Dinos and Diatoms are different and seem to have different tendencies when it comes to most things. Toxic dinos are the rule, Toxic diatoms the exception. The size of the toxins sounds to be very different. Domoic Acid (diatoms) is a small molecule, Ovatoxin, palytoxin, maitotoxin,(dinos) etc are big, and seems unlikely that the greatly different molecule structures would be doing the same job regarding metals. While diatom may generate the toxin change metal chemistry in the water, the dinos seem to do a good job of using their toxins to free up nutrients by killing a lot of organisms - bonus points for killing organisms that you've trapped in the mucus mat to keep the nutrient release super close by. So while it is true that dinos and diatoms seem to up toxin production in response to nutrient scarcity, it's not obvious that toxin production in dinos would be tied as closely to trace metal pressures.
But it may be worth a try, getting dinos to go non-toxic would definitely improve coral livestock outcomes. Activated Carbon may pull toxins from the water, but it seems minimally effective at protecting a coral colony that's become settled by a dino mucus mat. Things seem to go bad for that coral in a hurry.
The other concern that Randy mentioned is that even non-toxic dino blooms can be hard to eradicate.

 

[Randy Holmes-Farley Verified Community Expert]

Where is it suggested that added iron reduces dino toxin production? In the article above it didn't:

"Growth rate and cell yield in treatments without added iron were also significantly reduced to 70.1% (μ=0.16 day−1) and 34.2% (8003 cells ml−1), respectively, of those with iron added (μ=0.23 day−1 and 23,416 cells ml−1). No significant effect on YTX production was measured."

The domoic acid article just suggests trace element binding may be a utility of it, not that it changes when iron is increased.

 

[taricha]

The domoic acid article just suggests trace element binding may be a utility of it, not that it changes when iron is increased.

It did actually find more Domoic Acid under Fe-stress (low Fe), or Cu-stress (high Cu).

The more doubtful issue is what you pointed out - whether Dinos do the same in response to metal stress. Other papers show connection between general nutrient stress and dino toxin production, but I don't recall anything showing a metal connection.

edit: oh, I see what you actually wrote. yes - they did not show that removing the metal stress decreased Domoic Acid.

 

[Randy Holmes-Farley Verified Community Expert]

I am worried adding iron or other trace elements may make the dino problem worse, not better, but you won't know until you try.

 

[kecked]

I have a small tank that I’m willing to risk. My sentinels are star polyps. They close up when dinos are there even if not on them. I have no uv on them either. What I’m questioning is the form of iron. Should it be organic bound or inorganic like chloride. I guess if I add excess it will not matter.

Scratch that my wife says she added chemiclean last night. My control is no more.

What I read was somewhat indirect. Adding iron reduced the toxin production because the toxin is used to scavenge iron when it is rare. Sidephore. I was thinking the toxin would be reduced if the Dino’s were not Fe hungry but there is the overgrowth risk. I am not sure if the other competitors would be able to outcompete the Dino’s in that case.

What got me on this line was that I could not find toxin in my tank and had been using gfo. Once I stopped and then started dosing n and p I saw a toxic affect with my star polyps that was not there so I added the gfo back and dosed anyway and the effect went away. Since I was keeping p up manually, the only affect I could think of was the carbon I had it mixed in so I dropped that and did pure gfo. Still the toxic affect seemed less. Removed the gfo and held p stable and toxic effect returned. So the leach from the gfo has to be inorganic to start and solubility limited. We are not talking adding much. Then I saw the yeast and thought ok sidephore again.

Well that’s what this has been all about. Peeked my curiousity. I had hoped to repeat the experiment on my small tank that I infected on purpose for the task. So much for that!

 

[mcarroll]

My sentinels are star polyps. They close up when dinos are there even if not on them.

I wonder if octocorals such as your star coral might be feeding on dino cells (10-50µ-ish?) more than the more typical scleractinians found on the thread, and therefore suffering more from the toxins than most? Dino cells may be toxic even if the water column is not. (Dunno, just supposing.)

If this is what's happening, it seems like it would inspire the coral toward a polyps-in stance, for sure.

 

[kecked]

No idea but nothing else is affected. Not even my snails and crabs. In the tank my wife put the chemiclean they opened right up even though the Dino’s in the sand increased....cuz it prob killed the cyano holding it in check!

 

[kecked]

@Randy Holmes-Farley
http://reefkeeping.com/issues/2006-11/rhf/index.php

Might need to revise some of this article. Particularly the driving nutrients down and using gfo.

Guy added gfo in other thread and had Dino explosion. That is a data point to support Fe growth. Asked if his P remained high before he stopped and if he sees toxic effects. Looks like he repeated what I did.
Based on the explosive growth my idea is not a good one even if it drops toxins.

It would be amazing but unlikely we can find a limiting reagant specific to dinos

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley
http://reefkeeping.com/issues/2006-11/rhf/index.php

Might need to revise some of this article. Particularly the driving nutrients down and using gfo.

Yes, that's an issue with old articles in general is that as our knowledge and understanding of certain things changes, the article can become outdated. That said, some are not easy to update as I don't control them.

 

[kecked]

I really wasn’t trying to be bitchy. In fact I tried to private message you and don’t see it possible here....and for you with good reason! You’d be swamped.

Yes knowledge changes. Again thanks for the ear I appreciated it. I just want to contribute if I can. Thought I might have a way. I’ll keep trying to find ways.

Have a great weekend

 

[taricha]

Let me throw this GFO idea around.
This article talks about what GFO takes out, and what it adds.
https://www.advancedaquarist.com/2012/2/chemistry
Based on this article and other discussions, I think the standard view is that GFO does not contribute any usable form of iron to a tank.
It is known to pull a bunch of stuff out.
And yet we do see reports of people adding GFO to stable systems and seeing a sharp increase in growth of dinos etc.
(I'm distinguishing here between the long term P depletion effect, and taking about something else, much more short time frame)
It certainly seems like this is pointing towards some of the iron being (or becoming) usable.
Chasing down this path earlier, I ran across papers about cyanobacteria siderophores capturing iron that hadn't been available before, and now the diatoms with domoic acid playing a similar game.
So I've been of the opinion that there could very well be organisms in our system that are capable of taking this iron we consider unavailable and putting it into play. I've also felt like this would be nearly impossible to prove (short of identifying trichodesmium cyanobacteria in our tanks - I've looked. Never seen any lol).
@kecked, you were talking about something similar but with far blue light possibly doing this with no biological assistance needed. (What about Fe that takes a trip through UV fixture?)

 

[kecked]

http://www.aquionics.com/main/blog/iron-and-manganese-and-their-inhibitory-effect-on-uv-performance/

I must say at this point that we have tossed a lot of literature out of context back and forth. I’m putting this note here so who ever reads this in the future beware! For example I’m about to say iron accumulates on the glass sleeve in uv sterilizers and foul the ability of them to run. I’m basing that on a single web hit above. Might be true in industrial settings but to state that happens in our reef is really misleading to anyone reading this without this note. Same with the other links above. Full disclosure.

 

[kecked]

Seems from 5hevabove link iron can settle on the quartz sleeve. I don’t think there is enough energy to make iron excited in a uv unit especially in solution. That’s a guess. Photoelectric effect prob not. Even if it did it would transfer the energ6 rapidly to the water. Could there we a charge in 5he quartz from the uv that acts to attract the Fe? Maybe. E=hv. Don’t know. If it was intense enough yes. Common in air. I have no idea in a liquid interface. The link seems to say it does but those units are industrial size. There would have to be some forc3 to make the iron stick in such a fast flow. Yes flow is zero at the wall. 8 have no idea. Rambling.....bah

 

[Randy Holmes-Farley Verified Community Expert]

Let me throw this GFO idea around.
This article talks about what GFO takes out, and what it adds.
https://www.advancedaquarist.com/2012/2/chemistry
Based on this article and other discussions, I think the standard view is that GFO does not contribute any usable form of iron to a tank.

I think that may be incorrect.

Iron Oxide Hydroxide (GFO) Phosphate Binders by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2004-11/rhf/index.htm

Another possible role may be played by the iron itself. GFO is not completely insoluble. The solubility of iron hydroxide in natural seawater is small, but still significant (0.02 - 2 ppb), although it is largely controlled by the availability of organic ligands.11-13 One interesting possibility lies in the way that soluble iron actually impacts the precipitation of calcium carbonate.

At high concentrations, iron inhibits the precipitation of calcium carbonate. While different researchers find different threshold concentrations for this inhibition (>25 ppm in one case,14>7ppm in another case15), it is a well established and studied phenomenon. The mechanism is believed to be the same as for magnesium, phosphate, and organics, which all poison the growing calcium carbonate surface.

At much lower concentrations, however, iron actually increases the precipitation of calcium carbonate by acting as a site for nucleation of new crystals. In one case this happened at 100 ppb dissolved iron, increasing the rate of scaling (the precipitation of calcium carbonate on surfaces) by about 60%.14 In another case, the induction time for precipitation (that is, the time it takes for precipitation to begin once the water becomes supersaturated) was reduced by 40% at 1.4 ppm iron and the overall precipitation rate was increased by 32% at 560 ppb (lower iron levels were not tested).15 These studies were carried out in freshwater, and I have not seen similar studies in seawater.

Is the natural dissolution of GFO important in the nucleation of calcium carbonate precipitation? I am not sure. But it is clearly one possible explanation that fits the observations of aquarists as well as known phenomena involving iron.

 

[taricha]

Lolwut. On the quartz sleeve? That's certainly not one of the options I was considering.
Thank you for the disclaimer before taking us to crazytown.

 

[kecked]

Yes crazy town. I really thought I had a lot of this stuff sorted and find myself questioning if I even know what ph is anymore.

I posted in another thread that I find stuff grows on plastic more than anywhere else in the tank. Maybe it’s a carbon source! Polyesters have cobalt as part of their Catylist.

Stupid over and out....

 

[mcarroll]

Someone said all plastics are carbon sources. (Can't recall who.)

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, most plastics are not useful carbon sources. The chemical nature of the surface strongly impacts what cells attach. That's a big part of what a company I currently work with does. We are developing a wound treatment that provides appropriate attachment sites for human cells (to encourage healing), but at the same time prevents bacteria from infecting the wound by making the surface very undesirable for them (kills them).

 

[mcarroll]

I think it came up in the context of rodi storage containers.

Interesting about the high tech bandaids!!! Sounds way cool!