Chronically low Magnesium?

Jet915

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So Ive been testing magnesium for almost a year using salifert. I would usually get between 1240 and 1300. When it would dip around 1240 I would add about 100 ml of BRS magnesium to supplement and the magnesium would be noral for a month or so. For some reason, the last 2 months, my magnesium has been reading chronically low like around 1150 to 1200 and ive been supplementing 100 ml of magnesium every 2 weeks. I did switch to 2 part dosing a few months ago and have good coralline growth but magnesium usually shouldn't always be this low chronically right? I do 15 percent water changes every 2 weeks. Any thoughts?
 

Amboss72

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Anytime I have a change in my water chemistry that seems to coincide with the timing of new practices that I’ve incorporated in dosing or water changes I start there. As you are probably well aware manipulating your magnesium levels also has an impact upon your calcium and alkalinity levels. Randy has an excellent article on how changing one of these major minerals impacts the others. I’m sure you can google it or search it on this forum.
 

Randy Holmes-Farley

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I agree that it is likely the water change water being at that lower level. If you use a two part that does not contain enough magnesium, then that's another reason it will decline
 
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Jet915

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I agree that it is likely the water change water being at that lower level. If you use a two part that does not contain enough magnesium, then that's another reason it will decline
Ive never checked the Mg level of my change water but my salt has always been reef crystals. My 2 part is BRS, I dont think that has Mg right?
 

Eagle_Steve

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Reef crystals should be around 1330-1350 mag when mixed at 1.026. I think they advertise 1345 on the container, but I have had it usually mix around the range I listed.
 
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Jet915

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I actually dose additional Mg on my newly mixed salt water every week.....I would definitely start there.

How much are people dosing? I guess its not uncommon to dose Mg frequently?
 

Waters

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How much are people dosing? I guess its not uncommon to dose Mg frequently?
I only dose 1/2 cup with each Brute can......32 gallons I believe? It depends on your salt. I use Red Sea Blue which isn't horribly low, but low enough that I need to dose some extra each week.
 

little_sardines

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Also worth double-checking/recalibrating your refractometer, if your salinity is off your mag readings will be off - I made this mistake not too long ago, it's too easy to get lazy with some of the testing stuff haha.
 

beaslbob

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the improved diy two part system in the stickies on the reef chemistry form uses calcium chloride for calcium, baking soda for alk and Epsom salts and magnesium chloride for magnesium.

the first step is to get calcium , alk and magnesium all in line. in your case get magnesium up to 1350pm or so.

You might give that method a read and use the on line chemistry calculator to determing how much to add.

my .02
 

Randy Holmes-Farley

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Ive never checked the Mg level of my change water but my salt has always been reef crystals. My 2 part is BRS, I dont think that has Mg right?

The BRS recipe(which is my design) has a third part that is the magnesium part and it should not be ignored. :)
 
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Jet915

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The BRS recipe(which is my design) has a third part that is the magnesium part and it should not be ignored. :)
Oh, ok, it doesnt need to be dosed in a doser like alk and calcium right? Ive just been supplementing every 2 weeks.
 

beaslbob

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Oh, ok, it doesnt need to be dosed in a doser like alk and calcium right? Ive just been supplementing every 2 weeks.
using Dr. Randy holmes-farley's improved two part what you do is a one time setting of all parameters.
then when alk drops you dose equal amount of the calcium and alk solutions.
When you use up a 1gal of the calcium and alk solutions you dose 300ml of the magnesium supplement.

In my experience that brought the magnesium back up to 1350ppm or so.


my .02
 
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Jet915

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using Dr. Randy holmes-farley's improved two part what you do is a one time setting of all parameters.
then when alk drops you dose equal amount of the calcium and alk solutions.
When you use up a 1gal of the calcium and alk solutions you dose 300ml of the magnesium supplement.

In my experience that brought the magnesium back up to 1350ppm or so.


my .02

Ok thanks.
 
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