Really need help with Magnesium dosing

[Randy Holmes-Farley]

Seems unlikely anyone would know with the instructions being not to test.

Any I wouldn’t simply accept a mag kit result as evidence, but many RMM users get icp for other reasons, and I’ve not seen any of them show a problem.

 

[Randy Holmes-Farley]

In any case, I make no claims that RMM is perfect, only that it is less likely to be a problem than ordinary test and dose to target.

 

[UMALUM]

Wow. That’s quite a response.

Every time someone comes and posts about issues with magnesium based on home test results, I think it’s good advice to point them there. You can disagree, and feel free to state so the OP get a different view point.

And I am not telling people not to test, I think it’s better to use a more reliable test method and just use a little math to get there. I also suggested the OP test his newly mixed saltwater to see if his magnesium test kit was reasonable. Not sure what your beef is.

In this case the OP was considering how to dump a huge amount of magnesium into his tank based on a salifert test kit. I think a little caution to not blindly trust that kit is well placed.

You have yourself a fine

Wow. That’s quite a response.

Every time someone comes and posts about issues with magnesium based on home test results, I think it’s good advice to point them there. You can disagree, and feel free to state so the OP get a different view point.

And I am not telling people not to test, I think it’s better to use a more reliable test method and just use a little math to get there. I also suggested the OP test his newly mixed saltwater to see if his magnesium test kit was reasonable. Not sure what your beef is.

In this case the OP was considering how to dump a huge amount of magnesium into his tank based on a salifert test kit. I think a little caution to not blindly trust that kit is well placed.

You have yourself a fine day.

My issue is you have no evidence. Thread after thread with even the slightest mention of magnesium results in the same dumpster fire. The very definition of gaslighting is indeed promoting a method that calls for no testing only to turn around and say your not telling people not to test. Show me solid proof of all these big bad test kits and I'll shut up.

Not sure I need your permission to have a fine day.

 

[rishma]

My issue is you have no evidence. Thread after thread with even the slightest mention of magnesium results in the same dumpster fire. The very definition of gaslighting is indeed promoting a method that calls for no testing only to turn around and say your not telling people not to test. Show me solid proof of all these big bad test kits and I'll shut up.

Not sure I need your permission to have a fine day.

how about some evidence that I am not telling people not to test? I will quote a couple of relevant sentences from my first post in this thread. I suggested he validate the reasonableness of his test kit by testing newly mixed saltwater. That’s certainly not telling him not to test. You’ll also note that I state that I personally do not test magnesium except with ICP. That’s true and people can choose to think it’s a good idea or a bad one, but it’s what I do.

I have not tested magnesium in years except what I get in an occasional ICP. I’d be wary of adding that much magnesium based on a home test kit result.

Randy frequently suggest testing newly mixed saltwater to see if your magnesium test kit is reasonable.

But I will take the opportunity to share what testing I think is best for this. I only test alkalinity regularly and from that infer calcium and magnesium. This is what I do because I trust alkalinity tests, I trust the chemistry behind calcification, and I trust my ability to do the math. I trust all these things more than my ability to get an accurate magnesium and calcium home test result. I validate this approach with ICP.

I do not think I could have a successful reef tank without testing. I just believe I can do it without specifically testing magnesium at home. I am trying to help and share what I have learned.

 

[Randy Holmes-Farley]

Show me solid proof of all these big bad test kits and I'll shut up.

Will you? lol

It's easy to see lots of evidence of bad results. Many, many cases where folks say things like magnesium went up 150 ppm in a few days of no dosing. Or a decline, or whatever.

Or cases where two kits are used on the same water and the difference is huge. Obviously one or both are wrong.

Have you seriously never seen such comments? Do I need to find them for you?

 

[Randy Holmes-Farley]

Bear in mind that the hurdle of properly recommending one thing over another is merely that it is better.

It does not mean, nor does it imply that either one is always wrong or always right.

 

[UMALUM]

Will you? lol

It's easy to see lots of evidence of bad results. Many, many cases where folks say things like magnesium went up 150 ppm in a few days of no dosing. Or a decline, or whatever.

Or cases where two kits are used on the same water and the difference is huge. Obviously one or both are wrong.

Have you seriously never seen such comments? Do I need to find them for you?

Unfortunately, the burden of proof falls on the person or person's making the claim. LOL
I don't think a handful of bad kits justifies the fearmongering taking place especially without the evidence that the kits are being used correctly.

 

[Randy Holmes-Farley]

Unfortunately, the burden of proof falls on the person or person's making the claim. LOL
I don't think a handful of bad kits justifies the fearmongering taking place especially without the evidence that the kits are being used correctly.

Ok, I disagree, but to each his own.

 

[Randy Holmes-Farley]

Unfortunately, the burden of proof falls on the person or person's making the claim. LOL
I don't think a handful of bad kits justifies the fearmongering taking place especially without the evidence that the kits are being used correctly.

Proof that testing can give erroneous values. 2 tests 200 ppm apart. A few days ago. This type of result is very common.

Aqua spin test vs salifert test

Hey fellow reefers I have a question regarding my current tank testing. For weeks my large reef tank consistently reads high magnesium as I get my water aqua spin tested every single week for my reef tanks. I go to the same location every week so I trust them. Although I know the tests...

www.reef2reef.com

Thus, the rationale for RMM.

 

[rishma]

Will you? lol

Doubt it

 

[Miami Reef]

But I think it is perhaps cheaper to bottle tank water, get an ICP, then use that bottled tank water as a standard.

What do you think of this experiment where they showed the accuracy of magnesium results with different ICP manufacturers?

For Magnesium (Mg) none of the vendors delivered high precision

For Magnesium (Mg) --- Based on the above assessment I would be skeptical of any of the values reported by the vendors based on a control range of 140 ppm. The gage variability for all of the vendors for this element are all in the moderate range and approaching the top of the range with exception of one vendor. I would assume my test measurement to be equally valid and would make any adjustments according to my testing results. In addition I would validate and improve my test method.

How We Use ICP-OES Results Of Unknown Accuracy And Precision

ABOUT THIS ARTICLE This article was authored by @Dan_P, @taricha and @Rick Mathew. We collaborated in the development of the experimental methods, the cost of the project and the analysis of the data. The project was started in August of 2021 with the purpose of understanding the quality of the...

www.reef2reef.com

 

[Randy Holmes-Farley]

I'll note that the largest magnesium errors came from the now defunct ICP analysis. My recommendation for ICP is to use oceamo for magnesium for a variety of reasons, some of which Christoph addresses here:

Correctness and repeatability of ICP-MS seawater measurements

Skeptic or not, how do you decide on the amount of trace elements to dose or whether you have an elevated pollutant when the data can be rather uncertain? Certainly don't send samples to a bunch of ICP vendors. That way leads to madness :)

www.reef2reef.com

The higher the concentration, the more signal you are having, the smaller also the error. Typical error for macroelements is this in the 2-3% range, if performed well. For us this is still too much - this is why we are measuring Na, K, Mg and Ca in addition with cation chromatography since several months, which is even more robust and brings error down to the 1% range. We are also having a control sample (SST, system suitability test) we are measuring there in every sequence.

 

[Miami Reef]

Thank you for clearing that up.