iodine

[reefkeeper2]

I stopped dosing iodine a long time ago, thinking is was unnecessary. I also remember hearing Randy advising against it at one of our meetings. I thought my tank would get what it needed from the nori I feed daily. Anyway, I have been having some problems with my gorgonians looking pretty bad and I lost the blueberry a month ago. I remembered somewhere that I read that iodine was essential for the "shedding" some of the gorgonians do to rid themselves of algae on their surface. So I sent out my tank water to that new ATW water testing service and sure enough, the iodine level result came back 0ppm. I dosed Kents iodine 3 days ago and all the shriveled gorgs are now popping with polyps. You learn something new all the time in this hobby, so I thought I would share this in case anyone else has some unhappy gorgonians. Now I just have to nail down how much iodine to supplement.

[chew*]

Interesting, So even with a regular water changes the levels were at 0. In my case i dose 5ml of trace elements and coral vite with every water change, curiosity makes me want to test a fresh batch of salt water though.

[reefkeeper2]

I imagine what salt you use would have a significant effect, but so would using carbon and ozone. I use both. Also, a correction. It's AWT water testing, not ATW.http://aquariumwatertesting.com/

[fanaglethebagle]

Be careful, I overdosed on Iodine and now my cleaner shrimp was squiggly antenae from premature shedding.

[reefkeeper2]

Less is usually more with additives. I plan to dose according to directions for a month, then retest. I bet I don't need to use as much as the directions say, but we shall see.

[Andy O]

I dose the Kent iodine and usually dose half the amount that the directions suggest.

[stingythingy45]

I dose one cap of Kent iodine in a 55 gallon the weekends I skip the water change.I also dose a cap of Kent strontium/moly that weekend as well.
Then I do a 5 gallon water change every other weekend.
Seems to work for me.I have heard that skimming removes iodine and I have leathers and shrimp.But I must say I've seen hobbiest get lambasted by "some self knowledgeable people"about never dosing.Probably the same folks that are tending their undergravel systems.lol
The same people that will scream that iodine test are worth crap.
If I see,"don't dose without testing" 10 times a day I would be shocked.
Oh well...

[Greg Hiller]

Paul (reefkeeper2),

While I'm not doubting your experience I would keep in perspective that what you experienced might not have been related to the iodine addition. I've never heard of the iodine-benefiting-gorgonians connection. FWIW, the 'Blueberry' gorgonians (blue polyped non-photosynthetic) are known to be extremely difficult to keep.

My experience with (photosynthetic) gorgonians has been that those that shed tend to shed much more frequently in tanks with high levels of nutrients (in an attempt to get the algae off of them). Strong water motion helps the gorgonian a lot with both the shedding, and the reduction of growth of 'stuff' on their surfaces. Feeding the gorgonians with small particulate foods (newly hatched brine shrimp work really well) also seems to keep them quite healthy and growing.

[reefkeeper2]

Your right Greg. It's entirely possible that the change with the gorgs was coincidental with the iodine supplement. One of the challenges of the hobby is how to interpret what appears to be cause and effect. What we think is the result of a particular action on our part is actually not what happened at all. To really know the answer to this, we would need a controlled experiment. Gorgonians kept in a system with sea normal iodine and some kept in a system without. This is one of the problems that can make reefkeeping difficult. The lack of real data but an abundance of anecdotal testimony. I recall Mike P. spoke about this at the meeting today. I'm going to try and remember this in my future posts.
I think my goal will be to try and make the tank water as close to natural sea water as I can. An iodine level of 0 is certainly not normal, so supplementing to normal levels should do no harm. Of course without an accurate kit, I will have to send water samples out to see if my dosing is in line. I will use half of what the recommended dose is and retest in a month.

[Bobbofin]

I dose 2ml of iodide weekly, about 40% of the recommended dose for my tank size.

[Greg Hiller]

Paul, I recently read (not from the primary scientific literature though) that gorgonians do have a fair amount of iodine in their tissues. So maybe it really does help.

Since I've seen your tank (though I didn't have time to stay for the basement equipment tour) I assume you have a calcium reactor. If you do, I'd guess that some iodine will be being added to your tank as the substrate dissolves. Also, from what I remember in your tank, some of the gorgonians were pretty close to some stinging critters (the monster anemone in your avatar for example). Such contact will likely make them very unhappy, and likely to close up (though I realize you probably know that).

[reefkeeper2]

Actually, the gorgonian next to that anemone seems immune to its sting because it is often open with the anemones tentacles all over it. It's weird. I was going to move it, but since it does not seem to be aversly affected I am going to leave it be. It was the flat purple frilly one on the upper left that was refusing to open. The purple sea rods didn't look to great either. And of course I lost the blueberry but that could have been for other reasons.
I do have a calcium reactor. I use lots of carbon and ozone though. Maybe it's getting cleared out faster than it can be replaced. Any experience with the Salifert iodine test kits? I was thinking of getting one.

[Randy Holmes-Farley]

There are some gorgonions that are known to need iodine. I had not thought that any we keep fall into this category, but that may not be correct. Nevertheless, the evidence of supplemental iodine being beneficial is very limited, IMO, and I still recommend not bothering to measure or dose it. That said, however, if you have continued success using it and not without it, by all means continue.

Here's a section from one of my iodine articles:

http://www.advancedaquarist.com/issues/mar2003/chem.htm



Who uses iodine: Gorgonia and antipatharian corals (black coral)

Another set of creatures of the deep that use iodine are certain gorgonia, such as Plexaura flexuosa. They have 3,5-diiodotyrosine in their bodies, to the tune of 0.1 to 2.6% of the total dry weight as iodine. This iodoamino acid is presumably incorporated into proteins in the skeleton (stem), but the benefit is unclear. Again, it may be largely an antipredatory effect that is desired. The iodine incorporation in gorgonia seems to increase with age. The proteins of many different gorgonia species contain substantial iodine: Eunicella otenocalloides 6.5-8.9% by weight%, Gorgonia verrucosa 4.2-9.0, G. lamarcki 3.3-6.8, G. scirpearia 0.4-0.6, Rhipidigorgia flabellum 0.6-1.1, Euplexora maghrebensis 0.19-0.23, and Plexaura kukenthali 1.9-2.2.44 It has also been demonstrated that at least one gorgonia (E. verrucosa) takes up iodine in the form of inorganic iodine from the water column.

One study showed that the organoiodine compound thyroxine, and some related compounds, are localized to certain parts of the gorgonia L. virgulata. Most interestingly, one of the places it is localized to are scleroblasts (spicule-forming cells) and on the spicules themselves. Further, the addition of thyroxine to these cells impacted the uptake of calcium, and it is suggested that the thyroxine functions in spicule formation.

The antipatharian corals (the black corals) also seem to incorporate a lot of iodine. The basal regions of these corals are especially loaded with iodine, with more than 23% iodine by dry weight recorded in two species. Again, the specific purpose is not known.