Why can't I raise my Magnesium levels?

[Araona]

Ok I'm really confused as to why my Magnesium levels are so low, they are currently reading at 1020ppm and I've checked them twice with a salifert kit. I've just dosed red sea magnesium to raise the Mg levels by 20ppm,waited 15 minutes and tested again and absolutely no change! The freshly made saltwater made with red sea blue bucket is also coming out at 1020,what am I doing wrong?!

Other paramaters:
KH 9
Ca 395
Salinity 1.026 (just calibrated as well)

 

[blaxsun]

I would wait at least 24 hours before testing again because it can take that long to disburse in the tank. I would maybe take your water into a LFS or get a different testing kit to double-check the results, because unless you have a really bad batch - the magnesium in the Red Sea salt should be a lot higher.

 

[gbroadbridge]

Ok I'm really confused as to why my Magnesium levels are so low, they are currently reading at 1020ppm and I've checked them twice with a salifert kit. I've just dosed red sea magnesium to raise the Mg levels by 20ppm,waited 15 minutes and tested again and absolutely no change! The freshly made saltwater made with red sea blue bucket is also coming out at 1020,what am I doing wrong?!

Other paramaters:
KH 9
Ca 395
Salinity 1.026 (just calibrated as well)

You are either reading the test incorrectly or the test is faulty.

Double check the instructions. Are you perhaps reading the test backwards? I.e. amount left vs amount used from the syringe?

 

[Araona]

I would wait at least 24 hours before testing again because it can take that long to disburse in the tank. I would maybe take your water into a LFS or get a different testing kit to double-check the results, because unless you have a really bad batch - the magnesium in the Red Sea salt should be a lot higher.

Yeah it's meant to be a lot higher than this, I will check it again tomorrow

 

[Araona]

You are either reading the test incorrectly or the test is faulty.

Double check the instructions. Are you perhaps reading the test backwards? I.e. amount left vs amount used from the syringe?

Just double checked and no I am doing it right, I'm a scientist by profession so I'm pretty meticulous about testing instructions but it could possibly be a bad test, might be a good idea to try a different kit maybe

 

[DaJMasta]

The kits can be off, and a slightly different procedure can produce different readings.

As a baseline, that number sounds pretty low (though maybe less so with some salts), but I would both try and check your water with something else (lfs or friend test, icp, etc.) And then recheck your math on your magnesium supplement. If you mix it from dry, it's probably worth rereading the directions to make sure what you were dosing was the right strength.

 

[Garf]

Ok I'm really confused as to why my Magnesium levels are so low, they are currently reading at 1020ppm and I've checked them twice with a salifert kit. I've just dosed red sea magnesium to raise the Mg levels by 20ppm,waited 15 minutes and tested again and absolutely no change! The freshly made saltwater made with red sea blue bucket is also coming out at 1020,what am I doing wrong?!

Other paramaters:
KH 9
Ca 395
Salinity 1.026 (just calibrated as well)

Mag tests are a bit wobbly and I’m not surprised it’s not sensitive enough to pick up a 20ppm increase to be honest.
How are you calibrating your chosen salinity testing method?
Is the calcium and alkalinity in the new saltwater coming out at what it’s supposed to, or are they low also?

 

[Randy Holmes-Farley Verified Community Expert]

Ok I'm really confused as to why my Magnesium levels are so low, they are currently reading at 1020ppm and I've checked them twice with a salifert kit. I've just dosed red sea magnesium to raise the Mg levels by 20ppm,waited 15 minutes and tested again and absolutely no change! The freshly made saltwater made with red sea blue bucket is also coming out at 1020,what am I doing wrong?!

Other paramaters:
KH 9
Ca 395
Salinity 1.026 (just calibrated as well)

I agree that test error is by far the most likely explanation, even if the test procedure is followed exactly.
Low salinity is another, but if yours is correct, that's not the explanation.

A 20 ppm boost will be hard to detect by kit.

 

[Araona]

Mag tests are a bit wobbly and I’m not surprised it’s not sensitive enough to pick up a 20ppm increase to be honest.
How are you calibrating your chosen salinity testing method?
Is the calcium and alkalinity in the new saltwater coming out at what it’s supposed to, or are they low also?

I am using a refractometer with calibration fluid at 35ppt.
I haven't checked those on the new saltwater, got too distracted by the magnesium, I'll do it later and see!

 

[Spare time]

I'd just raise it to the level desired and then test.

 

[Araona]

I'd just raise it to the level desired and then test.

I have corals in the tank, will that not stress them if I raise by such a large amount?

 

[Propane]

How are your corals looking?

 

[Araona]

How are your corals looking?

They're all looking fine, there's a tiny patch of the green star polyp that has gone a darker colour and not opened up but everything else looks good and we've got all sorts in there

 

[Propane]

like you said above might be a good time to test with a different kit. Prolly no rush since things are looking good and you are dosing mag.

 

[Spare time]

I have corals in the tank, will that not stress them if I raise by such a large amount?

Not that I've seen. I don't think they care much. Not in my tank nor in others.

 

[Propane]

I have corals in the tank, will that not stress them if I raise by such a large amount?

It’s my understanding that around 1500 is where corals and snails start getting unhappy.

 

[Thumbster]

Ok I'm really confused as to why my Magnesium levels are so low, they are currently reading at 1020ppm and I've checked them twice with a salifert kit. I've just dosed red sea magnesium to raise the Mg levels by 20ppm,waited 15 minutes and tested again and absolutely no change! The freshly made saltwater made with red sea blue bucket is also coming out at 1020,what am I doing wrong?!

Other paramaters:
KH 9
Ca 395
Salinity 1.026 (just calibrated as well)

How are you mixing your saltwater?

I know a guy who was adding the salt first then adding the water and it made the levels really low because it precipitated out.

Some people I tell you.

 

[Idech]

I had a similar problem and it turned out to be a bad test. I waited too long to buy another test and ended up having really high mag levels in the tank.

Get a new test.

 

[Araona]

How are you mixing your saltwater?

I know a guy who was adding the salt first then adding the water and it made the levels really low because it precipitated out.

Some people I tell you.

Yeah water first then salt with a powerhead and heater on, seems the most logic way!

 

[Araona]

I had a similar problem and it turned out ti be a bad test. I waited too long to buy another test and ended up having really high mag levels in the tank.

Get a new test.

Thanks I am going to go tomorrow morning and get one!