'New' iron source..

[Samala]

Some of you may remember us all talking about iron sources for macroalgae and seagrasses, and how to provide it without ODing the tank, and without using gluconated forms such as those that Seachem uses for iron chelating. Gluconated molecules dont seem to be as stable in saltwater than the EDTA chelated ones mostly due to pH problems from what I know.

Found a nice product about a week ago that solves this problem, and doesnt have any superfluos additions other than a leetle bit of potassium, manganese, zinc and molybdenum. It's Kent Marine's Super Chelated Iron.

Analysis on the bottle says:

Soluble potash.. 3%
Iron (Fe) (Min).. 0.24%
Manganese.. 0.01%
Molybdenum.. 0.0000005%
Zinc.. 0.00014%

Certainly trace amounts on those trace elements, Zn, Mo and Mn. Dosing according to the bottle's suggestions gives a nice 0.05 ppm reading in my tank.

All in all, I like the product so far, and just wanted to give others a headsup on using it instead of Seachem's Fluorish Iron which I've mentioned before. You can still do DIY preps of chelated iron of course, but not everyone likes to play around with dry chemicals I realize.

>Sarah

[AIMFish]

I was about to start using that because the LFS sells Kent products. I was a little confused/suprised when I read the ingredients tho, only 0.24% iron! I assume it's, iron, isn't needed that heavily or it's hard to concentrate, since you mention keeping 0.05 ppm levels. I guess if they made it any more concentrated then it would be one of those "1 drop treats 20 gallons" products.

[billsreef]

I've been using a homebrewed concoction of iron citrate. Got the recipie from Randy. Interestingly Randy is using the Kent iron, last I knew, instead of mixing up gallons of his own brew

[Samala]

AIM.. its pretty easy to concentrate iron, but the problem is that the more concentrated a chelated source is, the faster it tends to fall out of solution, or precipitate, all over your bottle. And Kent is trying to make this dummy proof, or overdose proof, by keeping the concentration low. That way its really hard to OD the tank and endanger your animals, since, iron at high levels is a bad thing. Like you said, that way its not 1drop to 20 gallons kind of product.

So.. while you're paying for water mostly, this seems like a great little bottle to suggest to other reefers or those with heavy fuges. I find people balk less when I talk crazy chemicals if I suggest a product made by a marine manufacturer for a marine application.

Oh, and looks like this bottle should last through 125 doses.. about 2 years worth, a little more, on my 20gal tank. Not too shabby for $5. We'll see if I'm still in love with this product in a few months time.

>Sarah

[piercho]

Sarah,
how are you finding what the manufacturer is using as a chelator? I've got a gallon bottle of Azoo iron chelate, it was sold as intended for FW use. I didn't know there was a difference in what the chelator was.

[Samala]

I have a feeling only Seachem does the gluconated molecule route. The Kent Iron says it right on the bottle, iron EDTA. I guess Azoo doesnt have it listed in ingredients? I'd think that was strange.. dont they all have to list ingredients? Or, wait, probably not, this is the hobby application afterall. Their website is kind of a mess but doesnt say whats in it. Hmm.

Oooh hold on, Azoo sells plant hormones! Wow.. auxins and gibberellins. Interesting.

>Sarah

[3D-Reef]

Sarah,
I've been useing Kent's iron for some time now and a few weeks ago I got a Sea chem test kit.Now, I have been doseing at the rate it says on the back with little results, the test shows nothing in solution.So I've been doseing every other day.Now the greens are taking off.But still when I test I get a reading of zip..nadda...nothing.
Does this tester pick up the edta form of iron? Or does it ,(fe),fall out that fast?

[Samala]

Good to hear that someone else is using it and likes it. I wonder if your eelgrass has perked up any since you upped the dosages.

I am not sure that the Seachem iron test is very reliable. Many of the kits on the market are not that reliable and some are totally off. I use the Lamotte kit, which is pretty accurate against lab equipment, so I trust it. Its kit 7787, for FW or SW.. expensive and not alot of tests are the cons against using it though. I cant remember how I got ahold of it, perhaps marinedepot.

When I dose according to the Kent bottle the tests come up at the 0.05 level I recommend. I would think that would be true for other people's tank, barring much precipitation or other issues with the iron in suspension.

Honestly, the algae is going to be the best barometer of nutrients in the water column. If I've been dosing nitrates and I notice my green algaes look a bit weak, I know they're ready for more iron. If I get even a touch of diatoms, I know I've got too much!

>Sarah

[Randy Holmes-Farley]

FWIW, I am still using my home brew, but I think both Seachem's iron gluconate and Kent's EDTA iron are likely fine.

The EDTA iron is actually too strongly bound, and needs to be broken by UV or ozone to become bioavailable.

I've recently been recommending Seachems iron gluconate. It would be much more weakly bound, but may still be fine, as is the iron citrate that I dose.

I also not not think it desirable to dose so much iron that it shows on a kit. That is likely too much, IMO.

[Samala]

Hmm. Well now I have more questions. I thought we didnt want weakly bound iron forms in a saltwater environment to avoid precipitation problems. (?) And, since the Seachem gluconated stuff was intended for considerably lower pHs, that it may fall apart very readily in saltwater applications. (?)

I have been under the impression that it was advisable to have the molecules stay in suspension until used by the plants.

Randy I've been suggesting to dose until just readable on a reliable kit, on mine that level is 0.05ppm. Then not to dose again until you get a zero reading. Its hard to suggest to dose something to a non-readable level, as anyone could come back in a few days and still have a non-readable level present, but may think there is nothing in the tank at all.

Oh I should mention that all of this is intended for macroalgae heavy and seagrass aquaria, not a typical fuge application.. though I know some reefers dose iron to their fuges.

Do you have a level you strive for with dosing?

>Sarah

[Randy Holmes-Farley]

I'd say that I do not know for sure that the Seachem material is OK. I've not used it. But we are not really trying to keep large amounts in solution. It might even be fine if it transfers some iron to organics already in the water. Many folks have been successful with iron citrate, and it is not strongly chelated either.

Here's a comment that I made on dosing amounts:

First Iron Article: Macroalgae and Dosing Recommendations
http://www.advancedaquarist.com/issues/aug2002/chem.htm

frm it:

"Iron in Reef Tanks: How Much and What Form?

Deciding how much iron to add is fairly easy because, in my experience, it doesn’t seem to matter too much. Presumably, once you add enough to eliminate iron as a limiting nutrient, extra iron does not apparently cause harm (at least that I’ve detected in my tanks or heard of from others). I selected a dose of about 0.1 to 0.3 mL of a solution containing 5 g of iron (as 25 g of ferrous sulfate heptahydrate) in 250 mL of water containing 50.7 g of sodium citrate dihydrate. This liquid is dosed 2-3 times per week to my system with a total water volume of about 250 gallons. This iron(II) citrate has turned brown and cloudy since I first made up the bottle years ago, suggesting that it is oxidizing to iron(III) and some is precipitating from solution, but I still use it. Over the past 4 years, I’ve dosed nearly all of the 5 grams of actual iron to my tank.

Now that may sound like a huge amount, and it is. It’s enough to bring 800 million gallons of completely depleted seawater up to the 0.000006 ppm level that I mentioned earlier for natural sea surface water. Still, I’ve not noticed any problem, do not know the steady state concentration, do not know how high of a solution concentration is actually optimal for my tank, do not know how much is biologically available by the mechanisms mentioned below, do not know how fast it is removed by skimming and other mechanisms, and do not know what would happen if I cut it back by a factor of 1,000.

All that I know is that microalgae has never been a problem since starting the iron, and I’ve not noticed anything negative that I could attribute to the iron (nor have I heard of any from others doing similar dosing). Still, I don’t keep all organisms available to the hobby, and if you do seem to get a negative reaction from something, I’d advise backing off on the dose or stopping completely.

Since many hobbyists do not have access to the chemicals required to make iron(II) citrate, I’d advise buying a commercial iron supplement. There are a number available that seem appropriate and are not very expensive. Some commercial supplements combine manganese with iron (such as Kent’s product), presumably because the scientific literature has demonstrated that phytoplankton also scavenge manganese from the water column. I’ve not experimented with manganese, but it is probably fine to use if you cannot find a pure iron supplement.

I’d also advise using only iron supplements that have the iron chelated to an organic molecule. The iron sold for freshwater applications is sometimes not chelated because free iron is more soluble in the lower pH of freshwater tanks. I’d avoid those products for marine applications. It will likely still work (as many of the studies in the scientific literature use free iron in seawater), but probably not as well because it may precipitate before it has fully fortified the system with iron.

In many cases of iron intended for the marine hobby, the product may not tell you what the iron is chelated with, in order to protect proprietary formulations. I don’t actually know if it matters too much. Very strong chelation by certain molecules will actually inhibit bioavailability by not permitting release of the iron without completely taking apart the chelating molecule, but I expect that manufacturers have avoided those molecules. EDTA and citrate, and some others, actually degrade photochemically, releasing small amounts of free iron continually. It is believed to be the free iron that is actually taken up by many organisms, and likely iron(II), though some organisms may be able to convert iron(III) to iron(II) before uptake (the detailed absorption mechanisms are generally not known). There is a more detailed discussion of this degradation and uptake in “Captive Seawater Fishes� by Stephen Spotte (1992). "

[Paul B]

I have about a foot of rusty chain in the tank, does that count?

[piercho]

EDTA and citrate, and some others, actually degrade photochemically, releasing small amounts of free iron continually.

I'd almost take that as a recommendation FOR the EDTA-chelated Fe. Most people using halides hit their water pretty well with UV-rich light, don't they?

[3D-Reef]

Sarah,
Thanks for the tip on test kits.I'll order one this weekend.
As for the eel grass it's been doing great,so far, it's growing at a rate of one plant a week.If this keeps up I'll transfer more from the old system.
Randy,
Apprentice reef chemist here.
What got me started doseing iron was that I had grown 25 shaving brush plants but the other alge wouldn't grow.I dosed a little kno3 and poof, they went sexual.As a result one "h..."of a cyno out break.
Since then I've been removing the cyno and started dosing iron.With a once a week dose, not alot was growing.Now that I dose every other day everything green is taking off real good.It seems after three days of not dosing,the alge starts turning white and the cyno comes back.
Could iron help with removing po4 by precipatation? Or would it be more of the competition from the alge?

[Randy Holmes-Farley]

I'd almost take that as a recommendation FOR the EDTA-chelated Fe. Most people using halides hit their water pretty well with UV-rich light, don't they?

Perhaps.

Could iron help with removing po4 by precipatation? Or would it be more of the competition from the alge?

I doubt there is a lot of precipitation of iron phosphate, but it is possible. I expect it may just be the iron bioavailability that keeps things green.

[estrange]

I dosed exactly what it says on the bottle and the Seachem test still detects nothing. Anyone know what's going on?

[Randy Holmes-Farley]

Iron is usually dosed to levels below detection with test kits.

[Shoestring Reefer]

Are there "better" test kits available?

[Randy Holmes-Farley]

I do not think that iron kits are generally useful for the levels that marine aquarists dose.

[graveyardworm]

With all the hubub in this forum lately regarding FE dosing, and since I recently started a refugium with macro. I decided to try it for myself. I purchased the Kents iron and a Seachem test kit. Seachem caims that their kit can measure iron down to .01 which is what their instructions state as NSW levels. I tested prior to adding iron, and got a 0 reading. I then dosed 8 drops directly into my fuge. I havent retested yet, but this is an over 300 gal system and I dont expect 8 drops to be detectable. I was going to go the 8 drops per day like the instructions state rather than the weekly dosing. I'll be keeping a close eye on my livestock, I'll post back with any negative or positive changes. I have a mix of soft and sps corals as well as a small selection of macros. My plan was to dose daily until the test kit just barely shows concentration ( if it ever even shows concentration ) then maintain it there.

[NicoleRM]

Hmm when I read the bottle I took it to mean 8 drops per 50 gallons for the daily dosage. Am I gonna OD my tank?

[3D-Reef]

That is the correct dose.It's 5ml per 50 gal per week,OR, 8 drops per 50 gal per day.

[graveyardworm]

Hmmm, guess I should read dosing instructions again, although I think I'll keep it at 8 drops per day for now and see what happens, just to be on the safe side.

Just checked and my bottle says " Directions - Add one teaspoon or 5 ml per 50 gallons (200 liters) of tank capacity every week or 8 drops each day"

I take that to mean 8 drops per day regardless of capacity ( maybe someone else can clear this up because it doesnt seem very clear), and I wouldnt do any dosing without a test kit to verify that an OD is not occurring.

[Randy Holmes-Farley]

I purchased the Kents iron and a Seachem test kit. Seachem caims that their kit can measure iron down to .01 which is what their instructions state as NSW levels.

They would be wrong then. Surface sewater iron levels are on the order of 0.000006 ppm.

First Iron Article: Macroalgae and Dosing Recommendations
http://www.advancedaquarist.com/issues/aug2002/chem.htm

Second Iron Article: Iron: A Look at Organisms Other than Macroalgae
http://www.advancedaquarist.com/issues/oct2002/chem.htm

[graveyardworm]

Thanks for the correction with the NSW level, now it looks as though I have some reading to do.

Maybe I should've been more specific, the Seachems stated NSW level is .01 mg/L. Does that make more sense? I noticed in the first article it lists NSW levels at ( .1nM ) or ( 0.000006 ppm ). Maybe I should spend a little more time in your forum.