Quick help with MG reading

Lmcg

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Good afternoon everyone. I’m having a little bit of a dilemma with my tank. I noticed last week that my yellow hammer stopped opening. I did a water test to see if that could be the problem, and all of my numbers were OK, except Mg.
This is the results:
Ph- 8 API
NH3- 0 API
NO2-0 API
NO3- 10 (or a little less) API
PO4- .25 API
Kh- 9 Red Sea
Ca- 420 Salifert
Mg- 930 Salifert

Two weeks prior all reading were the same, except Mg was 1410. Everything was open and growing and doing great.

i ordered a new Salifert MG test and Just retested today. Everything Tested the same except MG was over 1500, had to use 10 more drops from second syringe. Tried the old test and got 960.

Now both hammers are closed and my torch is barely extending today. All other corals are looking fine.

Any idea what could be going on with the tests? Shouldn’t my Ca and Alk be going way off too if the Mg is that far off in either direction. Could one or both of the tests be bad?
 

phatduckk

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I've had test kits go bad even before they've expired. I usually chalk it up to me contaminating the reagent or some other user error.
I'd be really surprised to see Mg drop that much in 2 weeks, or ever... maybe Mg could drop that much if your ATO went crazy and dumped a bunch of RODI but you' see a drop in dkh and CA too.

Anything whacky with your salinity? My next step would be to verify the salinity is in a good range
 

Lmcg

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I've had test kits go bad even before they've expired. I usually chalk it up to me contaminating the reagent or some other user error.
I'd be really surprised to see Mg drop that much in 2 weeks, or ever... maybe Mg could drop that much if your ATO went crazy and dumped a bunch of RODI but you' see a drop in dkh and CA too.

Anything whacky with your salinity? My next step would be to verify the salinity is in a good range

I thought that too. It’s been pretty consistent at 1.025 1.026. I keep a notebook with all my test results and all the way back to April 11th they have been very consistent, only very minor fluctuations. It’s driving me nuts since both MG test readings are so drastically different and neither result is a good one. Could both the old test kit and the new one be bad?
 

Lmcg

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No one near by that I know personally. Most people I know think I’m out of my damn mind having a reef tank.
Im was going to do my water change this afternoon, anyway, so I’ll test again after. Then take a sample over to the LFS to get tested. It’s about 45 minutes away.... NJ weekend traffic and rain = headache and extra stress.But it’s worth it to know which test is accurate.
 

phatduckk

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Do the water change and see how it goes. 900 sounds nearly impossible to me especially since alk and ca are in line.

then theres the question of why the coral are upset..,
 

mattzang

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i really don't trust magnesium tests at all. i've tried red sea and salifert and both give numbers, but when i've checked them against triton they're usually at least 100-200 points off.
 

Jessican

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@mattzang I’ve found that the ICP results pretty closely match the Trident readings on the 525, but definitely not any of the manual tests on the other tanks. Those are always pretty significantly off, like you mentioned.
 

Lmcg

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i really don't trust magnesium tests at all. i've tried red sea and salifert and both give numbers, but when i've checked them against triton they're usually at least 100-200 points off.
At this point I’d take 100 or 200 points off. It’s better than 600 point difference from 2 different tests.
 

mattzang

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not really, 100-200 points off was both higher and lower than the actual value. so if i tested 1100 mg with salifert and 1500 with red sea, but the actual number via triton was 1300ish. i'd send in a triton or icp test to really know. the 930 number seems especially questionable to me as i'm not sure that number could be possible, chemically. you'd need to neglect it for a long time and never do water changes and use some super low mg salt to begin with. and if you're in the ballpark of 1200-1500 you should be fine assuming you aren't pouring in 100s of mLs of mg a day

my original point was mg tests in the hobby are utter garbage compared to alk and calcium tests, which i've found to be fairly reliable based on triton tests. so if you think your corals are suffering due to chemistry, i suggest sending in a lab test. in the mean time i suggest looking for other possible issues as i'd venture to guess it's probably not magnesium
 

Lmcg

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Hey, thanks for all the help with this. I was able to get the Mg tested at an LFS and they said 1520. It’s a little high but it looks like the new Salifert test is good. So I chucked the old kit out.
After a 20 percent water change yesterday, the torch is a little better today, and the peach hammer is out a little. The yellow hammer is still fully retracted. I used the last of my water so I have 25 gallons mixing now, so I’ll do another 20% in the morning and keep my fingers crossed.
 

clsanchez77

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I have had magnesium test kits give inconsistent reading before. I was getting low reading on the Seachem tests and it caused me to overcorrect magnesium considerbaly over the course of a few months. It was not like I tested consistent values, and then it was suddenly low. Rather, the test kits crept downward overtime. By the time I figured it out, it was too late.

Now I am using the AquaForest test kits and they are reading extremely high. Ive been intending to test their own saltwater batch to see if it my tank water or the test kit.
 

Lmcg

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After two 20% water changes, I gave things a few days for things to calm down. The hammers that were fully retracted are finally starting to slowly peak out again, and the torch is about halfway back to normal. I have noticed that my pink Goni and my acan have been a little moody though the last few days.
I also added chemi pure instead of the carbon.
Since the problem wasn’t the MG level, but the test Kit being no good. I’m curious as to what could be throwing things off. The corals in question have been healthy and growing like crazy, same locations, same light, same flow. The only change for them really has been the addition of an elegance (currently being harassed by the assassin female Clownfish), and a decent size green leather. Could there be a little chemical warfare going on?
The leather when fully open was coming in contact with a gorgonian, which has since been moved. The gorgonian was winning that battle and left a nice dull tan spot on the leather, which has mostly healed up.
 

Lmcg

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Hey, thanks for checking in. Things seem to be getting almost back to normal. Obviously it wasn’t a drastic swing in the mg, new test kit, So alls good there. Everything is back to normal, except the Goni is still mostly retracted, and one of the hammers is still being A little moody. The other hammer, and the torch are at 100%. So is the Acan, in fact I noticed 2 new heads started. Not sure what irritated them, but it seems to have cleared up.
I’m wondering if there may have been a little chemical warfare after I added the leather and the elegance.
 
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