My Iron always reads 0?

[schriss]

First of all I do not do water changes. So I test for Iron as I read corals need it for some reason. Test kit is the newest from Red Sea. It reads 0 for the last 2 weeks.
So I bought Brightwell Ferrion, dosing max dose 10ml once a day.
Today tested and still light blue (zero). If it was anything like pink/red, it would be in high range. But it is very light blue, meaning 0.
Why would that be? Can it be that heavily stocked 20 gal tank can absorb all the Iron I'm dosing?
I have read you can't really overdose Iron, so I was thinking about doubling the dose and see what happens, but wanted some advice first.

[Randy Holmes-Farley]

It should always read zero. No kit can read low enough to detect natural levels of iron.

Iron takes only a tiny bit to be more than enough.

This has more:

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

from it:

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.

[schriss]

I might be mistaken, but that new Red Sea Iron Pro test kit is a new line of their test kits and it appears to be working.
Here is a YouTube video of it taking a measure and reporting in OK range, the colors are matching 0.25 range. In my case I always get light blue = 0.
Having read the article you posted (thanks!) I will double the dose for few days and see what happens. I'm sure I cant overdose as it's not an iron in powder but a dilluted Brightwell Ferrion product.

[Randy Holmes-Farley]

Working, perhaps, but indicating that you have a very high overdose of iron.

I'd stop dosing.

Surface seawater, as noted above, has 0.000006 ppm of iron.

I do not believe that 0.25 ppm is "OK". It is too high.

[schriss]

Found this in Red Sea documentation:

Optimal level 0.15 ppm of total iron (chelated and non-chelated) in an artificial reef aquarium
Overdose
Toxic to all invertebrates above recommended levels. Common indication
of overdose is a darkening of the corals due to excessive Zooxanthellae
growth and the outbreak of nuisance algae. Can cause regression
of the soft tissues in SPS corals. In case of over dosing change 50 %
of the water and reduce the supplementing dosage by 50%.

OK I guess I stop dosing for now and read some more...
Any other comments?

[Randy Holmes-Farley]

I would not rely on that statement, nor the kit. I've never heard of anyone dosing that high of an amount to a reef aquarium. My opinion is that far, far lower is more than enough. Folks get very clear positive and rapid results with macroalgae when dosing far, far less. In my case, for example, I occasionally dose about 0.001 ppm, and assume it drops well below that between doses.

For comparison, Seachem in their Marine Trace, says it has 0.0007% iron, and to dose 5 mL per 80 L. So that's 0.035 mg iron in 80 L, or 0.004 ppm right after dosing.

[blakers82]

Any updates, Schriss? Have you continued dosing or left the Ferrion on the shelf? Any Results?

[schriss]

Hi, I stopped dosing because I got distracted by something that was happening then, don't remember what it was but when something happend I usually cut down on many non essential additives. So I stopped dosing Ferrion long time ago. I think it was the time I tried to figure out why do I get some cyano and some almost instantly browning and dying off algae, but I'm dosing bacteria to deal with NO3/PO4 which is tricky sometimes so that's most likely the cause.
So anyway, not even thinking about Ferrion at the moment.

[sweet_tweety68]

Hi Randy, I make myself thought about your iron(II)citrate solution. You take for 250 mL water 50.7 g of sodium citrate dihydrate and add 25 g of ferrous sulfate heptahydrate. Looking to molecular weight of FeSO4 · 7H2O is 278.01g/mol and the molecular weight of HOC(COONa)(CH2COONa)2 · 2H2O is 294.10 g/mol, what mol proportion is your solution, 1:2 or? How to you get the 50.7 g sodium citrate dihydrate?

[disc1]

Fe(II) ? Oops, I got that one wrong a little while ago. I assumed you would end up with Fe(III) in the end anyway after it hit the seawater.

[sweet_tweety68]

No, that is not correct. Ferrous iron formed a tridentate complex with citric acid, [Fe(II) cit]-, involving two carboxylic acid groups and the hydroxyl group, and was resistant to biodegradation. However, oxidation and hydrolysis of the ferrous iron resulted in the formation of a tridentate ferric-citrate complex, [Fe(III)OH cit]-, which was further hydrolyzed to a bidentate complex, [Fe(III)(OH)2 cit]2-

@ Randy: Can you tell me, why you take exactly 50.7 g sodium citrate dihydrate. Can you describe the calculation for me.

[Randy Holmes-Farley]

From the article:

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.

5 g of iron = 89.5 mmoles

50.7 g of sodium citrate dihydrate = 172.4 mmoles


So the ratio comes out 1.93 citrate to iron.

I believe that I initially got the recipe from a very old reefing book, but it is close to a 1:2 ratio.

[mund]

My iron always reads 0 too....

I have the red sea kit and although everyone says they want it to go too high I am just following what red sea recommends. if they are wrong im willing to pay the price.

So I dosed half of what it told me to dose yesterday when it showed 0 and now its showing 0 again.

Is it because its so needed right now that everything is sucking it up and it's going to take some time to catch up?

This is confusing as I understand levels should be undetectable but if I dosed yesterday why is it still undetectable?

[disc1]

How much did you dose? What should that bring the level to? How low does the test go?

[mund]

50ml every other day for 3 days.

I moved my post here in hopes that Red Sea can shed some light on this.
http://www.reefcentral.com/forums/sh...7#post22363307

[mund]

Here is the guide for testing/supplementing Iron (red sea coral colors c)

http://www.redseafish.com/wp-content...-GB-_2013B.pdf

1ml will raise the Iron level of 100 liters (25 gal) by 0.02ppm

So I should be adding about 60ml to get it to 0.15. I have been adding 50ml instead.

[mund]

removed, site didn't display previous post until after I posted so it was a duplicate post

[disc1]

How much did you dose? What should that bring the level to? How low does the test go?

This is a duplicate on purpose. I hit the same weirdness the last poster did and I'm not sure the first one made it in right.

[mund]

Please see above for dosing amounts. 50ml x 3 for 3 days within the week.

It says I should dose 60ml (1ml per 0.02 multiplied by 8(200 gallons divided by 25))

If I used 60ml it should bring it to 0.15 but I dosed 50ml each time for a total of 150ml that week.

the test measures down to 0.00.

[disc1]

No test measures to zero. Even million dollar mass specs have a limit of detection. Zero means below the limits of the test. What is the smallest number bigger than zero that it can give you.

[mund]

The test goes down to 0.00. It can't go to say 0.009 or 0.003947928374928.

[disc1]

Originally Posted by mund

The test goes down to 0.00. It can't go to say 0.009 or 0.003947928374928.

The test does NOT go down to zero. Can it measure 0.0000000000000001 ppm? No. That's bigger than zero. What is the smallest positive value it can read? What is the limit of detection of the test? If you can't answer that then I can't help you.

What is the smallest number it can give you that is bigger than zero?

I'm not asking about precision, which is what your previous post seemed to think. I am talking about limit of detection. What is the lowest amount of iron that it can register?

[mund]

Originally Posted by disc1

The test does NOT go down to zero. Can it measure 0.0000000000000001 ppm? No. That's bigger than zero. What is the smallest positive value it can read? What is the limit of detection of the test? If you can't answer that then I can't help you.

What is the smallest number it can give you that is bigger than zero?

I'm not asking about precision, which is what your previous post seemed to think. I am talking about limit of detection. What is the lowest amount of iron that it can register?

Seriously? That is exactly what i'm saying. Let me rephrase.

The test goes down to 0.00xxxxxxxxxxxxxxxxxxxx. It can't go to say 0.009 or lower.

[disc1]

Originally Posted by mund

Seriously? That is exactly what i'm saying. Let me rephrase.

The test goes down to 0.00xxxxxxxxxxxxxxxxxxxx. It can't go to say 0.009 or lower.

I thought i was clear we are looking for the smallest number larger than zero that the test can read. That is called the limit of detection.

Now that I'm home I went ahead and looked up the RedSea test and the LOD is 0.05ppm. You have on the color card, 0.00, 0.05, 0.10, 0.15... So the smallest number bigger than zero there is 0.05. That's the smallest positive result it can give. Any lower than that is going to look like zero.

[disc1]

Is that like the test you have?