Mag or Gag: Do you test magnesium?

Do you test magnesium? (Tell us why or why not in the comments!)

  • Yes, I test magnesium.

    Votes: 128 57.4%
  • No, I do not test magnesium.

    Votes: 88 39.5%
  • Other (please explain!).

    Votes: 7 3.1%

  • Total voters
    223

Reefing_addiction

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Still, the mag drop was test error.
It may have not been as low as it seemed, but it was still significantly lower than normal I would imagine for it to test that low multiple times. I did not trust the first test…but 4 test all at the same level seemed to say that my mag had indeed dropped a fair amount.
 

Dburr1014

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It may have not been as low as it seemed, but it was still significantly lower than normal I would imagine for it to test that low multiple times. I did not trust the first test…but 4 test all at the same level seemed to say that my mag had indeed dropped a fair amount.
This is why I would want to test, even if it's once or twice a year. It doesn't make sense to me* to never* test.
 

Reefing_addiction

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This is why I would want to test, even if it's once or twice a year. It doesn't make sense to me* to never* test.
ICP test would be the way you should go then…I would assume magnesium is one of the test that would be better suited and give you a proper level. I know that some of the things they test (trace minerals) are still a little wishwashy just due to their lower limit for it to register. (If I’m remembering everything I’ve read correctly). @Randy Holmes-Farley could definitely clarify for me here.

The only reason I would test mag and calcium frequently at home would be because of an influx of corals. They take time to settle in and start sucking up all the stuff they need and once they do it tends to make numbers do weird things.

I think sending in an ICP test 2 times a year is a great way to check the overall health of a tank. I was considering doing it quarterly.
 

Cichlid Dad

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Contrary to trends of late, yes I test. Every week. I have a lot of frogs and hammers and I believe magnesium is important to them. I hear test are inaccurate. Well if I test new water and it matches what is claimed, I have that level maintained in my reef, after water changes it remains the same then IMHO the test are accurate enough to keep them safe and stable in my reef
 

Reefing_addiction

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Contrary to trends of late, yes I test. Every week. I have a lot of frogs and hammers and I believe magnesium is important to them. I hear test are inaccurate. Well if I test new water and it matches what is claimed, I have that level maintained in my reef, after water changes it remains the same then IMHO the test are accurate enough to keep them safe and stable in my reef
If I can test the same water several times and get the same results I feel the same.

Although I believe weekly testing is a bit much - especially if you’re dosing. Unless you change something drastically or add a bunch of new stuff bi-weekly or even monthly for magnesium would work. You would more than likely see a drop in calcium prior to a drop in magnesium. I tend to only test Alkalinity and if that drops I test the others because that’s where you normally see the swing first (just my 2 cents)
 

PharmrJohn

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I voted yes in anticipation of what I'll do when my 197g goes up. My goal is to maximize coral growth, so I'll be testing, pretty routinely, Ca, Mg, ALK and pH (my goal parameter-wise will be 460 to 470,, ~1380 to 1400, 11-12 and 8.2 to 8.4).
 

PharmrJohn

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Curious that the same folks saying this still sometimes add things they cannot test for, such as vitamins, amino acids, organic carbon sources, bacteria, peptides (FM bolus dosing plan), many zeovit and other brand products of unknown composition, etc.
Of all on this list I was planning on dosing just AA. I'm curious.....Is this not good practice? Or would water changes pretty much cover it? Or is is necessary at all? My reasoning behind the action was really nothing more than I read it somewhere. I know....Lame.
 

Miami Reef

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Of all on this list I was planning on dosing just AA. I'm curious.....Is this not good practice? Or would water changes pretty much cover it? Or is is necessary at all? My reasoning behind the action was really nothing more than I read it somewhere. I know....Lame.
Randy was pointing that the old wives tale “don’t add anything you can’t test for” could be ironic because many people making that statement unknowingly add things they can’t test for.

Dosing Amino acids are a good way to add nitrogen to a system. Some of the things Randy mentioned can be useful in reef tanks (foods, carbon dosing, etc) despite not being able to test them.
 

PharmrJohn

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Randy was pointing that the old wives tale “don’t add anything you can’t test for” could be ironic because many people making that statement unknowingly add things they can’t test for.
Gotcha. Understood. Thank you.
 

Dburr1014

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Randy was pointing that the old wives tale “don’t add anything you can’t test for” could be ironic because many people making that statement unknowingly add things they can’t test for.
Is it an old wives tale?
To add context, would you tell somebody to add alkalinity if they didn't know what it was to begin with?
Probably not. My point is some things you should measure even if it's rarely measured before dosing certain things.
I think it would be hard to overdose aminos and things like that but easily to overdose alkalinity or magnesium or calcium.
Carbon, I guess would be easy to overdose and catastrophic.

I guess what I'm trying to say is certain water ions if you can measure, you might as well measure, just so you know where they're at.
 

Cichlid Dad

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If I can test the same water several times and get the same results I feel the same.

Although I believe weekly testing is a bit much - especially if you’re dosing. Unless you change something drastically or add a bunch of new stuff bi-weekly or even monthly for magnesium would work. You would more than likely see a drop in calcium prior to a drop in magnesium. I tend to only test Alkalinity and if that drops I test the others because that’s where you normally see the swing first (just my 2 cents)
I use AFR and at times have to hand dose 2 part to correct parameters. I run my magnesium 1424-1450. So because AFR is not perfect, weekly monitoring my system is required. 1 size solutions do not exist . I know my system and was stating what I do.
 

Miami Reef

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Is it an old wives tale?
To add context, would you tell somebody to add alkalinity if they didn't know what it was to begin with?
Probably not. My point is some things you should measure even if it's rarely measured before dosing certain things.
I think it would be hard to overdose aminos and things like that but easily to overdose alkalinity or magnesium or calcium.
Carbon, I guess would be easy to overdose and catastrophic.

I guess what I'm trying to say is certain water ions if you can measure, you might as well measure, just so you know where they're at.
I won’t get into too much detail, but absolutes are rarely accurate. There are exceptions most of the time.


Telling someone, “Don’t add anything you can’t test for,” isn’t helpful, nor does it educate the reefer on why you said that.


I’d venture to say most of us add things we can’t test for.
 

Dburr1014

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I won’t get into too much detail, but absolutes are rarely accurate. There are exceptions most of the time.


Telling someone, “Don’t add anything you can’t test for,” isn’t helpful, nor does it educate the reefer on why you said that.


I’d venture to say most of us add things we can’t test for.
Your right, absolutes not accurate.

My point is, putting it a different way, if you can have/buy/test for something that is to be a known range to have a successful reef tank and consciously not by or use it or test for it, why would you think you would always have that parameter in that range? There can always be outliers that make it fall out of range and you may never know it.

This is why some of us choose to have/own/use that test kit.
 

Reefing_addiction

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I use AFR and at times have to hand dose 2 part to correct parameters. I run my magnesium 1424-1450. So because AFR is not perfect, weekly monitoring my system is required. 1 size solutions do not exist . I know my system and was stating what I do.
Got it.
And yes 1 size fits all does not really exist
And how my tank thrives is different from yours
I run Aqua Forest Lab Component for dosing needs….

I was just stating that Alk is a good indicator of the other numbers and you will likely see it move before calcium and magnesium … that’s all
 
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Miami Reef

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“Don’t add alkalinity without ensuring it stays within this recommended target range.”

I think that’s a good way to say it.
 

Randy Holmes-Farley

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Gotcha. Understood. Thank you.

Amino acids are especially useful in low N situations ( as noted by Miami), and aspartic acid may be especially useful for corals. I’d treat dosing aminos as an experiment, looking to see if it was useful or not. :)
 

Miami Reef

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Amino acids are especially useful in low N situations ( as noted by Miami), and aspartic acid may be especially useful for corals. I’d treat dosing aminos as an experiment, looking to see if it was useful or not. :)
Can aspartic acid possibly be helpful if N is sufficient?
 

Randy Holmes-Farley

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I guess what I'm trying to say is certain water ions if you can measure, you might as well measure, just so you know where they're at.

I’d be all for testing if kits were accurate enough. Once a month is plenty frequent enough since it can’t really deplete more than about 2 ppm per day,but accuracy is still the issue.

Too many times I see people report wild changes in a few days using a single magnesium kit (which is not happening) or they have two different kits with very different values in the same water.

Thus, the question is: how valuable is it really, especially since we have a very good handle on the possible range of depletion rates in reef tanks based on more easily measured calcium consumption.
 

Randy Holmes-Farley

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Can aspartic acid possibly be helpful if N is sufficient?

That has been suggested tangentially in the scientific literature, where it was suggested corals have a significant need (it binds calcium and so may help in calcification) and it was suggested that corals do not make enough, but get it from various sources in the water.
 
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