Magnesium low

[FRANK48]

My mag is 1080 i tested with two kits and both came out the same.
alk is 8.5
Ca is 420

should I dose magnesium. I haven’t ever dosed before.

 

[bushdoc]

If Mg is truly 1080, yes, but it’s still somewhat questionable number due to Mg hobby tests being a bit less reliable than other tests. What salt are you using and what is your sg/salinity?Are you dosing Ca and Alkalinity? Mg consumption is generally a fraction of Ca/dKH consumption, so most probably it’s still a testing error or low sg of your saltwater or both.

 

[FRANK48]

If Mg is truly 1080, yes, but it’s still somewhat questionable number due to Mg hobby tests being a bit less reliable than other tests. What salt are you using and what is your sg/salinity?Are you dosing Ca and Alkalinity? Mg consumption is generally a fraction of Ca/dKH consumption, so most probably it’s still a testing error or low sg of your saltwater or both.

Salt I use is Red Sea coral pro
Salinity is 1.023 I’m currently raising it.
I have never dosed anything before

 

[AtlantiCat]

I've had the same problem and I'm using Instant Ocean Reef Crystals. I'm beginning to suspect this isn't the best quality salt. I just add a little Magnesion from Brightwell Aquatics when I do a water change and I'm good for a week. I keep only Zoas, dwarf Cerith snails, and Sexy Shrimp for the record.

 

[Rugops]

What test are you using.

Edit: Nvm

 

[Rugops]

I've had the same problem and I'm using Instant Ocean Reef Crystals. I'm beginning to suspect this isn't the best quality salt. I just add a little Magnesion from Brightwell Aquatics when I do a water change and I'm good for a week. I keep only Zoas, dwarf Cerith snails, and Sexy Shrimp for the record.

Yeah, I have a bucket of instant ocean that has really low magnesium. I can't remember the exact value but it was below 800.

I have my Mg at 1600.

 

[homer1475]

I've used regular old purple box IO for the better part of 20 years. I test every batch I make, never seen it below 1300.

 

[bushdoc]

Salt I use is Red Sea coral pro
Salinity is 1.023 I’m currently raising it.
I have never dosed anything before

Very unlikely that with this sg and with this particular salt brand Mg is so low. It is most probably testing error. I would bring sample to LFS or/and do ICP analysis.

 

[thatmanMIKEson]

Hard to have alkalinity and calcium in target range with low magnesium and low salinity, I'd get a second test kit or test again and make up a 5 gallon bucket of salt water to 35ppt and retest. Like mentioned this is more than likely testing issue but test the test to be sure.

Coral pro should mix very close to this

 

[FRANK48]

Hard to have alkalinity and calcium in target range with low magnesium and low salinity, I'd get a second test kit or test again and make up a 5 gallon bucket of salt water to 35ppt and retest. Like mentioned this is more than likely testing issue but test the test to be sure.

Coral pro should mix very close to this

Alright will do. I’m testing with salifert test kit btw. What are the best test kits for each parameter

 

[thatmanMIKEson]

Alright will do. I’m testing with salifert test kit btw. What are the best test kits for each parameter

Salifert is good enough, just fine

 

[FRANK48]

Very unlikely that with this sg and with this particular salt brand Mg is so low. It is most probably testing error. I would bring sample to LFS or/and do ICP analysis.

Just re tested and now it’s saying my mag is 1170

 

[DHill6]

I’ve also had low mg with TMPro salt, smaller buckets pu red chased well before before the salt issue. Tested with 2 different Nyos test kits. I just put a scoop of TM MG in sump, when the LPS look off its low mg in my case. It’s possible.

 

[bushdoc]

Just re tested and now it’s saying my mag is 1170

With your sg/salinity, last results seem more probable and it falls withing testing error. If you have FOWLR tank, I would leave it like it is, if you have mixed coral tank, I would raise sg to 1.025-1.026 and it should raise Mg by its own.

 

[DHill6]

I’ve also had low mg with TMPro salt, smaller buckets purchased well before before the salt issue. Tested with 2 different Nyos test kits. I just put a scoop of TM MG in sump, when the LPS look off its low mg in my case.

Should’ve read purchased, phone phonics

 

[FRANK48]

With your sg/salinity, last results seem more probable and it falls withing testing error. If you have FOWLR tank, I would leave it like it is, if you have mixed coral tank, I would raise sg to 1.025-1.026 and it should raise Mg by its own.

Thank you very much. I will do that

 

[Randy Holmes-Farley Verified Community Expert]

Just re tested and now it’s saying my mag is 1170

A perfect example of why I say it may not be worth testing at all due to inaccuracy.

Raise the salinity to 35 ppt (sg = 1.0264) from sg + 1.023 and that value becomes 1355 ppm.