Dosing iron for green/yellow SPS?

[uglyfish]

Red Sea's Reef Care program says to get good green / yellow coloration in corals, iron should be maintained at 0.15ppm. NSW iron is much lower... I read 0.0034. http://www.seafriends.org.nz/oceano/seawater.htm

 

And I've read the article in advanced aquarist about iron as a limiting nutrient: http://www.advancedaquarist.com/2002/10/chemistry

but still don't have a definitive answer. Said to work in macroalgae tanks - not overtly harmful to other corals in moderation... Some corals may expel zooxanthellae, or zooxanthellae density may increase... Cyanobacteria may decrease or increase... (?)

 

I've tested my iron with Red Sea's test kit and I'm reading 0 (undetectable). I'm not sure if I should bring it up to Red Sea's recommended 0.15. I looked at this specifically because my green acros are not coloring at all, while the blue/purple/pink are coloring strong.

 

Is anyone dosing iron in an sps tank? With what results?

[wombat]

I dose iron at around 5 ppb per week in SPS tanks. I have a sneaking suspicion that it is a limiting nutrient that is important in keeping Acropora palmata in captivity (there are only a couple people in the world who have success keeping this coral more than a year or so).

 

0.15 ppm is so ridiculously incorrect it's not even funny. Iron is measured in the parts per trillion range in surface seawater. There is really no point in trying to test it with hobby test kits. It is far too low in concentration to be detected without super fancy tools.

 

As Randy states in the AA article, there really is no harm in adding moderate amounts of it to your tank and observing your animals. Some people have reported good results in paled out Montipora recovering with Fe and Mn additions.

 

FWIW you need to add it chelated to something. I use the recipe of sodium citrate and ferrous sulfate that Randy recommends. You can also buy it in a bottle from Julian at Two Little Fishies.

[uglyfish]

I dose iron at around 5 ppb per week in SPS tanks. I have a sneaking suspicion that it is a limiting nutrient that is important in keeping Acropora palmata in captivity (there are only a couple people in the world who have success keeping this coral more than a year or so).

 

Thanks for your reply. Why did you decide dose iron? Do you have an acropora palmata? What improvements did you notice? Did you experience any side effects like algae or cyano? Do you grow macroalgae in your system (refugium)?

[wombat]

Thanks for your reply. Why did you decide dose iron? Do you have an acropora palmata? What improvements did you notice? Did you experience any side effects like algae or cyano? Do you grow macroalgae in your system (refugium)?

 

After reading Randy's article on iron and Julian's article on Goniopora in AA magazine. No side effects like algae or cyano. I noticed Halimeda growth increased a bit. Montis and green Acros look better. I don't have a refugium on these tanks.

[Genj]

How does GFO impact iron levels, and is it in a form that is even usable by the livestock?

[wombat]

Good question. Some Fe (III) will probably dissolve but that is not a form of iron that is readily available. Fe (III) can be reduced to Fe (II) but this requires anoxic conditions. This may be occurring in reef aquariums but the extent or whether or not it is happening is unknown. It is extremely difficult (expensive) to distinguish between the two in seawater.

[uglyfish]

How does GFO impact iron levels, and is it in a form that is even usable by the livestock?

 

I found an article about gfo and effects on trace elements... http://www.advancedaquarist.com/2012/2/chemistry

 

Like wombat pointed out - it appears most iron coming from gfo is not in soluble form. Total iron rises, but not the iron in a useable form. Wombat smart.

 

I found the article on Goniopora by Sprung on AA. Seems iron may benefit a few other corals like bleached trachyphyllia. http://www.advancedaquarist.com/2002/12/inverts

 

Wombat, on what size tank are you dosing iron? Can you give more details about iron dosing regime? Since you can't really test for it, how do you know how much to add or when it's depleted?

[wombat]

I dose it on tanks ranging from 100 to 4000 gallons. The recipe and dosing amounts are included in Randy's article. I think it winds up being somewhere in the neighborhood of 10ppb as Fe (II) per week. Been doing this for several years. I make no effort to test for it.

 

http://www.advancedaquarist.com/2002/8/chemistry

http://www.advancedaquarist.com/2002/10/chemistry

 

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.

 

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.

 

Two Little Fishies also makes a good iron/manganese product. If you do make it yourself, I would suggest diluting Randy's recipe by about 10x when making it and increasing the dose accordingly. His recipe tends to turn brown and oxidize to Fe (III) within a few months.

[Genj]

This is a great topic, one which I have very little to add, but like to learn about. I think there is so much to learn on human use of trace elements by following the way corals use them.

[NanoTopia]

I picked up a bottle of Brightwell's Iron Supplement a couple of weeks ago, I'm dosing way under the recommended amount. I am playing it safe and still offering my corals a little extra Fe. No negative effect to report, I have noticed some increase coloration with my green corals.

 

I have had trouble with bryopsis in the past so I am moving cautiously with Fe dosing.

[uglyfish]

I dose it on tanks ranging from 100 to 4000 gallons. The recipe and dosing amounts are included in Randy's article. I think it winds up being somewhere in the neighborhood of 10ppb as Fe (II) per week. Been doing this for several years. I make no effort to test for it.

 

I read Randy's first article on iron - so, iron doesn't seem to hurt anything, and the method of dosing is to dose lightly, and if you visually notice a problem, then cut back on dosing.

 

I think there is so much to learn on human use of trace elements by following the way corals use them.

 

Kind of... but I think people are different than corals. I found many articles on trace elements, but some are too complicated for me to understand - and most don't apply to aquariums.

 

I picked up a bottle of Brightwell's Iron Supplement a couple of weeks ago, I'm dosing way under the recommended amount. I am playing it safe and still offering my corals a little extra Fe. No negative effect to report, I have noticed some increase coloration with my green corals.

 

The increased green coloration is good to hear.

[uglyfish]

I sent an email to Red Sea asking about their recommended iron levels. I received a prompt reply and fair explanation from Red Sea. They know their recommended dosage is relatively high, compared to NSW - but they say it's important for coral growth and coloration and is safe at those levels. 0.05-0.15ppm is enough for good iron uptake by coral. When dosing iron, iron levels should be tested 30-60 minutes after dosing to ensure iron has not been overdosed.

 

The reply is in line with Randy Holmes-Farley's findings that a little extra iron really does no harm.

 

Ok.

[Genj]

I sent an email to Red Sea asking about their recommended iron levels. I received a prompt reply and fair explanation from Red Sea. They know their recommended dosage is relatively high, compared to NSW - but they say it's important for coral growth and coloration and is safe at those levels. 0.05-0.15ppm is enough for good iron uptake by coral. When dosing iron, iron levels should be tested 30-60 minutes after dosing to ensure iron has not been overdosed.

 

The reply is in line with Randy Holmes-Farley's findings that a little extra iron really does no harm.

 

Ok.

 

We are talking about this stuff right?? RS Iron

[uglyfish]

We are talking about this stuff right?? RS Iron

 

That's Red Sea's iron supplement. It contains other trace elements, but from what I understand iron is the main ingredient and you test iron levels before and after dosing it. I was curious about iron in general - and I'm not sure what the chemical difference between two little fishies iron and red sea's iron are.

 

The topic of iron dosing in a reef aquarium is fascinating to me because it seems to have quite alot of impact on coral coloration and health and in general. While hobby seems to focus on cal, alk, mag, no4, po4 as the primary gauge of water quality, there are so many trace elements that also play important roles. I think this process of learning and discovery is why so many of us are so addicted to reefkeeping. Any new information on the subject is welcome.

[uglyfish]

Interesting thread about iron dosing and the danger to clams. Old news I guess... but new to me.

 

http://www.nano-reef.com/forums/index.php?showtopic=74863