Iron dosing in presence of phosphate

[nematode]

I have a reef tank with 2-3 ppm nitrates and 0.2 ppm phosphate yet growth of algae on the glass is negligable even a week after scraping the glass. there are lots of collunista and stomaletta snails in the tank and they are probably doing some of the control, but even chaeto won't grow under these conditions. So I thought there might be an iron limiting situation.
I found the reciper from Holmes-Farely for Fe(II) citrate dosing solution. Seems reasonable to try.
But, also reading on line looking at the Dutch synthetic reefing system, I noticed that system doses iron to reduce phosphates. This makes some sense since GFO (granular Ferric oxide) is used to reduce phosphates. But R F-H iron is an Fe(II) iron, and ferric oxide is an Fe(III) compound.

So my question is can dosing iron using Fe(II) citrate be effective in the presence of phosphates, or will it simply precipitate out as some iron phosphate compound and be unavailable for biological usage by our corals and algae.

I also am aware that in general it is difficult to accurate test for the level of iron in our tanks. (and I don't have an iron test.). So looking for the experience of others with regards to this matter.

 

[Brad Miller]

Bump

 

[Randy Holmes-Farley]

I have a reef tank with 2-3 ppm nitrates and 0.2 ppm phosphate yet growth of algae on the glass is negligable even a week after scraping the glass. there are lots of collunista and stomaletta snails in the tank and they are probably doing some of the control, but even chaeto won't grow under these conditions. So I thought there might be an iron limiting situation.
I found the reciper from Holmes-Farely for Fe(II) citrate dosing solution. Seems reasonable to try.
But, also reading on line looking at the Dutch synthetic reefing system, I noticed that system doses iron to reduce phosphates. This makes some sense since GFO (granular Ferric oxide) is used to reduce phosphates. But R F-H iron is an Fe(II) iron, and ferric oxide is an Fe(III) compound.

So my question is can dosing iron using Fe(II) citrate be effective in the presence of phosphates, or will it simply precipitate out as some iron phosphate compound and be unavailable for biological usage by our corals and algae.

I also am aware that in general it is difficult to accurate test for the level of iron in our tanks. (and I don't have an iron test.). So looking for the experience of others with regards to this matter.

Yes, it will be effective.

 

[Darth.Daddy12]

I have a reef tank with 2-3 ppm nitrates and 0.2 ppm phosphate yet growth of algae on the glass is negligable even a week after scraping the glass. there are lots of collunista and stomaletta snails in the tank and they are probably doing some of the control, but even chaeto won't grow under these conditions. So I thought there might be an iron limiting situation.
I found the reciper from Holmes-Farely for Fe(II) citrate dosing solution. Seems reasonable to try.
But, also reading on line looking at the Dutch synthetic reefing system, I noticed that system doses iron to reduce phosphates. This makes some sense since GFO (granular Ferric oxide) is used to reduce phosphates. But R F-H iron is an Fe(II) iron, and ferric oxide is an Fe(III) compound.

So my question is can dosing iron using Fe(II) citrate be effective in the presence of phosphates, or will it simply precipitate out as some iron phosphate compound and be unavailable for biological usage by our corals and algae.

I also am aware that in general it is difficult to accurate test for the level of iron in our tanks. (and I don't have an iron test.). So looking for the experience of others with regards to this matter.

Dosing iron is dangerous in a tank as you need very little and can quickly kill everything. You normal salt mix should have more then enough and if not change salt mixes or increase water changing. Iron is a needed mineral for plants which is many times why some have issues with cheato to start with. You reasoning on this sounds solid however I wouldn’t ever try to dose minor or trace elements solo. Best to just use them as part of a trace elements dose or as part of salt mix during water changes as this will solve this 100% wo risking a tank crash.

The reason is.. there is no good way to test so you’ll be dosing blind.. never dose what you can’t test for.

 

[Dan_P]

I have looked at iron (II) gluconate in a fish only system using the Hanna low range iron Checker.

In agreement with Randy’s observation, the iron level does not last very long in the system. I monitored 0.2 ppm disappear within several days, and yet, a sample of tank water containing iron (II) gluconate lasts many days. PO4 level was unaffected.

One export mechanism is the skimmer. I found ppm levels in the skimmate but have not done a mass balance study to determine what portion of the chelated iron is removed by the skimmer. I also suspect GAC may remove chelated ion but haven’t tested this hypothesis yet.

I cannot comment on whether iron (II) citrate behaves similarly to the gluconate.

My initial interest in iron was to ensure my Caulerpa was not iron limited, but have not seen any response to dosing. I stopped dosing but plan to finish studying the fate of chelated iron in my system.

If you are curious about the reaction between iron citrate and PO4, do the study on a sample of aquarium water. Do it on a 1 or 2 L scale or even a 5 gallon bucket full of water from a water change. Dose the water sample as you would your system (proportionally smaller ) and monitor PO4 over several days. Unless you are really interested, skip buying the iron test. I have been disappointed with brand name iron tests which fail to detect chelated iron. If there is a significant amount of precipitation, you might see the PO4 decline quickly. You will need to make sure that you are adding enough iron to detect a change in PO4. If you need further ideas concerning the chemistry, I will take a shot at the stoichiometry.

 

[Randy Holmes-Farley]

The thing is, most dosed iron is likely precipitated anyway, whether iron oxide or iron phosphate or other solids. Nevertheless, the natural level of iron is so very low, that even 1% of the dosed iron staying available for organisms is way more than enough.

So no, precipitation is not a concern,

 

[Randy Holmes-Farley]

Dosing iron is dangerous in a tank as you need very little and can quickly kill everything. You normal salt mix should have more then enough and if not change salt mixes or increase water changing. Iron is a needed mineral for plants which is many times why some have issues with cheato to start with. You reasoning on this sounds solid however I wouldn’t ever try to dose minor or trace elements solo. Best to just use them as part of a trace elements dose or as part of salt mix during water changes as this will solve this 100% wo risking a tank crash.

The reason is.. there is no good way to test so you’ll be dosing blind.. never dose what you can’t test for.

I don’t agree with this. It is not dangerous (unless you may include encouraging pests like algae), and is demonstrably useful in some tanks (the owner of ReefCentral added iron on my advice and within 1 day his caulerpa was much darker green and grew faster over the next week).

 

[Darth.Daddy12]

I don’t agree with this. It is not dangerous (unless you may include encouraging pests like algae), and is demonstrably useful in some tanks (the owner of ReefCentral added iron on my advice and within 1 day his caulerpa was much darker green and grew faster over the next week).

But how much iron is really needed that’s the issue. It’s such a small amount unless you have a system that you don’t do regular water changes even if just 10% bi weekly.. there should be more then enough. Not to mention anyone going prolonged periods of time between water changes is dosing and most of that will have more then enough. Now if your system is very mature and stable and you rarely change water and alk needs are more then dosing can provide so your running a reactor then I can see dosing trace elements but not just iron. If you’re deffceint in iron then you’ll also be deficient in several key things needed by both corals and plants to grow. Being the mod of a major site I can see where he is likely as I described being super stable no water changes and using a cal reactor so yes some minor and trace things need to be dosed but just iron?

Here my issue.. how do you test for iron to know how much to dose or not dose? For the average reefer... you can’t. So you’re blind leading the blind and as slow as iron is consumed you can over dose easily same as potassium. Another minor needed for plant growth much more so then iron is. Now if you have shrimp that haven’t molted in a while you can observe Thier molting and figure out if you’re needing iron.. but then the question is how much and how often? I would tell someone they are lacking minor and trace elements and have them dose that per directions before ever having anyone try and dose these thing separately.

Not disagreeing with the premis and not knowing that specific situation I can’t disagree that it was the right call but I do take issue with the average reefer trying to implement an iron only dosing. I don’t see how they could ever maintain a proper amount when they don’t even know what amount they are starting with or how much what they are adding is effecting the tank.

 

[sixty_reefer]

Iron and iodine, some algaes consume this more than others

 

[Darth.Daddy12]

Iron and iodine, some algaes consume this more than others

Yet they are plants and in order to use either they first need potassium. But again how do you dose and measure for either to know how much is needed or how much your lacking? Outside an icp which is a snap shot 1 month old by the time you get the results..

 

[Darth.Daddy12]

Yet they are plants and in order to use either they first need potassium. But again how do you dose and measure for either to know how much is needed or how much your lacking? Outside an icp which is a snap shot 1 month old by the time you get the results..

Again I’m not debating the premis I’m taking issue with the fact we can’t on average test for these things and dose them in proper amounts. Any one can be very harmful when overdosed. It would be wiser to increase water changes schedule or amounts and let the salt mix take care of this for you or to use a minor and trace element combo as directed by a reputable Conakry who’s spent the time and money to figure out the right ratios. There is a reason certain things are packaged together in certain amounts and that’s cause they are consumed in those proportions. Even the best of the best test kits we can’t truley even measure nitrates accurately and now we want to dose things we can’t even begain to measure at all? This just isn’t logical. I’d feel more comfortable using a freshwater planted tank fluval essentials elements pack before just using random things I can’t properly measure. This is not a recipe for long term success.

 

[sixty_reefer]

Yet they are plants and in order to use either they first need potassium. But again how do you dose and measure for either to know how much is needed or how much your lacking? Outside an icp which is a snap shot 1 month old by the time you get the results..

Unfortunately without an icp is just luck or good intuition. There’s no way to find the right amount. If you going to dare to go that way you could just add a 1ml and see how things react. Iodine depends on wich one you decide to go but it’s risky.

 

[Darth.Daddy12]

Unfortunately without an icp is just luck or good intuition. There’s no way to find the right amount. If you going to dare to go that way you could just add a 1ml and see how things react. Iodine depends on wich one you decide to go but it’s risky.

Exactly my issue. It’s safer to use a full minor and trace elements package and dose that then just one or two of these directly. They already did the math for us.

 

[sixty_reefer]

Exactly my issue. It’s safer to use a full minor and trace elements package and dose that then just one or two of these directly. They already did the math for us.

I think I’ve read about a product targeting this issue the other day, can’t remember what brand it was but it had a lot of important traces for algae growth definitely safer to use if you not going the icp way.

 

[Randy Holmes-Farley]

But how much iron is really needed that’s the issue. It’s such a small amount unless you have a system that you don’t do regular water changes even if just 10% bi weekly.. there should be more then enough. Not to mention anyone going prolonged periods of time between water changes is dosing and most of that will have more then enough. Now if your system is very mature and stable and you rarely change water and alk needs are more then dosing can provide so your running a reactor then I can see dosing trace elements but not just iron. If you’re deffceint in iron then you’ll also be deficient in several key things needed by both corals and plants to grow. Being the mod of a major site I can see where he is likely as I described being super stable no water changes and using a cal reactor so yes some minor and trace things need to be dosed but just iron?

Here my issue.. how do you test for iron to know how much to dose or not dose? For the average reefer... you can’t. So you’re blind leading the blind and as slow as iron is consumed you can over dose easily same as potassium. Another minor needed for plant growth much more so then iron is. Now if you have shrimp that haven’t molted in a while you can observe Thier molting and figure out if you’re needing iron.. but then the question is how much and how often? I would tell someone they are lacking minor and trace elements and have them dose that per directions before ever having anyone try and dose these thing separately.

Not disagreeing with the premis and not knowing that specific situation I can’t disagree that it was the right call but I do take issue with the average reefer trying to implement an iron only dosing. I don’t see how they could ever maintain a proper amount when they don’t even know what amount they are starting with or how much what they are adding is effecting the tank.

It is a very small amount needed if alk you want to do is maintain natural levels, but regular water changes do not apparently satisfy the need, and overdosing dues nit generally lead to toxicity. It is very rapidly depleted, hence the lack of accumulation and lack of problem from dosing too much.

 

[Randy Holmes-Farley]

Exactly my issue. It’s safer to use a full minor and trace elements package and dose that then just one or two of these directly. They already did the math for us.

How is that safer? Maybe I don’t need or want them all.

 

[Randy Holmes-Farley]

Yet they are plants and in order to use either they first need potassium. But again how do you dose and measure for either to know how much is needed or how much your lacking? Outside an icp which is a snap shot 1 month old by the time you get the results..

There is a lot of of potassium in seawater, unlike fresh water. It never depleted in my tank, and there’s no inherent reason it should. But some folks may use foods that do not have enough potassium relative the the N and P present, and they may need to add some.

 

[MabuyaQ]

Again I’m not debating the premis I’m taking issue with the fact we can’t on average test for these things and dose them in proper amounts. Any one can be very harmful when overdosed. It would be wiser to increase water changes schedule or amounts and let the salt mix take care of this for you or to use a minor and trace element combo as directed by a reputable Conakry who’s spent the time and money to figure out the right ratios. There is a reason certain things are packaged together in certain amounts and that’s cause they are consumed in those proportions. Even the best of the best test kits we can’t truley even measure nitrates accurately and now we want to dose things we can’t even begain to measure at all? This just isn’t logical. I’d feel more comfortable using a freshwater planted tank fluval essentials elements pack before just using random things I can’t properly measure. This is not a recipe for long term success.

And how do you know that you are not adding more with water changes or commercial products than was consumed of those same trace elements you 'can't' test for without ICP?

You don't and these producers know it so all these products contain safe dosages at the lower end.

Trace elements like Fe, Cu+Zn, Mn and Ni are all used as/in antioxidants produced by zoöxanthellae and help prevent coral bleaching (if I remember correctly Fe is used most but there is a strong relation with temperature where Mn actually helps prevent bleaching at bleaching inducing temperatures and Fe induces bleaching at those temperatures (not certain if that was at low/in the absence of sufficient Mn).

So regular ICP testing to confirm manual tests conducted before and after dosing Fe and Mn and other elements are powerfull tools to get the most out of your corals. This is also where ion specific testing in the future can become a very powerfull tool.

 

[Dexter_SA]

Heres a interisting link of one of our local members were things went south

Dead tangs after dosing iron

It is a very sad morning for me as I lost my 2 yellow tangs which I had for the last 7 years and my regal tang. Last night I added some Seachem flourish Iron to the tank according to the dosing instructions (5ml per 200L) on the bottle. I dosed iron since I have a large amount of chaeto and...

www.marineaquariumsa.com

 

[Randy Holmes-Farley]

I think it very unlikely the iron killed fish. People lose fish all the time for unknown reasons. That said, this dose of iron was not intended for a marine tank and is much more than I would dose.

That product is 10,000 ppm iron. He dosed 5 mL per 200 l. So the dose was 0.25 ppm. I dosed my tank about 1-2 ppb, or a hundred times less.