Does AFR provide sufficient iodine for gorgonians?

Euphylliaphyle

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I have recently acquired a Purple Ribbon Gorgonian. I read elsewhere that gorgonians require iodine for tissue building. Does minimum daily dosing of AFR (5 ml/ 25 gal water) provide sufficient iodine (34 mg/l AFR) for gorgonian care, or do I need to supplement iodine beyond that? If so, what should I use, and how much?
 

Randy Holmes-Farley

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Yes, various gorgonia are one of the very few organisms we keep with a known need for iodine to build their structures.

It is not possible to answer if AFR has enough, since it obviously depends on how much you are dosing. A tank of just gorgonia would not use alk and calcium, and so would have a low demand for AFR and likely not enough.

If I had such a gorgonia, I would take one of two approaches.

1. Dose a fulll NSW level of iodine (as iodide) once a week, then after a few weeks get an ICP to see where it stabilized a few days after the last dose.

or

2. Dose the full NSW level of iodine (as iodide) once a week, and just assume its an adequate rate.

Of course, the update rate of iodine from the tank will depend on what else is growing in it, especially macroalgae of various types, and microalgae.
 

Randy Holmes-Farley

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Be careful as you can overdose iodine..

Highly recommend you do ICP tests until you get the level stabled.

Have you seen negative effects of elevated iodide?
 
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Yes, various gorgonia are one of the very few organisms we keep with a known need for iodine to build their structures.

It is not possible to answer if AFR has enough, since it obviously depends on how much you are dosing. A tank of just gorgonia would not use alk and calcium, and so would have a low demand for AFR and likely not enough.

If I had such a gorgonia, I would take one of two approaches.

1. Dose a fulll NSW level of iodine (as iodide) once a week, then after a few weeks get an ICP to see where it stabilized a few days after the last dose.

or

2. Dose the full NSW level of iodine (as iodide) once a week, and just assume its an adequate rate.

Of course, the update rate of iodine from the tank will depend on what else is growing in it, especially macroalgae of various types, and microalgae.
Thanks. I am dosing AFR for my LPS and SPS, not for the gorgonian or other softies. I am dosing 5 ml AFR in my 36 gallon tank (32 gals water). That is recommended starting amount for 25 gals. I just started with AFR, so it's a slightly conservative amount to start. I presume that all things being equal (agreeing with your point above that they are not!) AFR provides NSW iodine levels at stability based on Alk? I have no macros, but plenty of turf algae. Hopefully, that's transient.
 

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Have you seen negative effects of elevated iodide?
I started dosing Two little Fishies Iodine aug or sept of last yr. Towards the end of the yr i keep saying to myself that ALL of my LPS including the two gonis have been retracting. In Dec i purchased an icp test kit and got the result back right after NY. I had critical reading of iodine and ATI recommended to add carbon along with WC.
I added carbon for 3wks along with weekly WC and stopped dosing iodine completely.

All of the LPS are back to normal for the last ~20 days.
Im actually doing another ICP sometime this wk.
 
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Thanks. I am dosing AFR for my LPS and SPS, not for the gorgonian or other softies. I am dosing 5 ml AFR in my 36 gallon tank (32 gals water). That is recommended starting amount for 25 gals. I just started with AFR, so it's a slightly conservative amount to start. I presume that all things being equal (agreeing with your point above that they are not!) AFR provides NSW iodine levels at stability based on Alk? I have no macros, but plenty of turf algae. Hopefully, that's transient.
Sooo...

WATER from the upper layers of the ocean contains some 40 µgm./l. of iodine compounds¹

AFR label claims 17 mg iodine per 500 mL (34,000 µgm./l, or 170 µgm./5ml daily dose AFR, or 1.40 µgm/l system water replenished daily.

This is further confounded by water changes.

I guess there is an ICP test in my future.


¹ SHAW, T., COOPER, L. State of Iodine in Sea Water. Nature 180, 250 (1957). https://doi.org/10.1038/180250a0
 

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Yes, various gorgonia are one of the very few organisms we keep with a known need for iodine to build their structures.

It is not possible to answer if AFR has enough, since it obviously depends on how much you are dosing. A tank of just gorgonia would not use alk and calcium, and so would have a low demand for AFR and likely not enough.

If I had such a gorgonia, I would take one of two approaches.

1. Dose a fulll NSW level of iodine (as iodide) once a week, then after a few weeks get an ICP to see where it stabilized a few days after the last dose.

or

2. Dose the full NSW level of iodine (as iodide) once a week, and just assume its an adequate rate.

Of course, the update rate of iodine from the tank will depend on what else is growing in it, especially macroalgae of various types, and microalgae.
Is there an iodine test kit you recommend? I've been dosing a small amount for about a year but never tested due to the belief that a reasonably accurate affordable kit isn't made.
 

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I like RHF two options above. Dose to NSW levels, wait a bit, then send off an ICP. Or dose and don't send off the ICP. Assuming the dosing amount is correct. Other than that it sounds like a single Gorgonian so not sure there is a big concern here just yet. I keep a couple Corky Sea Fingers in my 210 and AFR seems to be fine.

I had a couple of low ICP results (ATI), bumped it up, and carried on. I can't say if it was the Gorgonians or something else consuming it as it is a mixed reef. Just added it and that was it. Nothing was different before, or after other than the ICP results.

Side note: I did an ICP sample in Fiji and at that location iodine came back 78.71(µg/l).
1770047586617.png
 

Randy Holmes-Farley

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Thanks. I am dosing AFR for my LPS and SPS, not for the gorgonian or other softies. I am dosing 5 ml AFR in my 36 gallon tank (32 gals water). That is recommended starting amount for 25 gals. I just started with AFR, so it's a slightly conservative amount to start. I presume that all things being equal (agreeing with your point above that they are not!) AFR provides NSW iodine levels at stability based on Alk? I have no macros, but plenty of turf algae. Hopefully, that's transient.

AFR cannot hope to provide NSW levels of iodine in all systems. No method can that is not adjusted by testing iodine in each individual circumstance. I think the best that can be said is that it provides "some" iodine, and that may be adequate for most reef tanks. There is no fixed relationship between iodine uptake and alk uptake.
 

areefer01

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AFR cannot hope to provide NSW levels of iodine in all systems. No method can that is not adjusted by testing iodine in each individual circumstance. I think the best that can be said is that it provides "some" iodine, and that may be adequate for most reef tanks. There is no fixed relationship between iodine uptake and alk uptake.

Unrelated, I remembered that Tropic Marin discussed iodine a while back here and ended up increasing the amount in All For Reef. I had to find the thread, link below.

 
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Euphylliaphyle

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AFR cannot hope to provide NSW levels of iodine in all systems.
Of course. I didn't mean to imply (or state) that. I figured my salt mix would take care of the bulk of it, just hoping AFR could sustain it. I get your point that I'll never know without testing. Thank you for helping me think through this, as always!
 

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Of course. I didn't mean to imply (or state) that. I figured my salt mix would take care of the bulk of it, just hoping AFR could sustain it. I get your point that I'll never know without testing. Thank you for helping me think through this, as always!

Iodine is depleted quite fast in many systems. Often just days from NSW levels to far less. The iodine in the salt mix doesn't really do much for iodine.
 

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