Mg rising?

tklb

New member
Hoping someone can help me understand why my Magnesium is rising. I have a 120G with a lightly stocked mix of LPS & SPS. I have a Neptune DOS and I dose Reef Fusion 1 & 2 (Alk & Calcium). I Have been measuring Mg every week or so, and when it falls below 1300ppm, I manually does Ions (Mg) to get back to my target of 1300ppm. All was going well, until Mid October.

On 10/12 I measured my Mg at 1280 with my Red Sea Mg Test kit. I did the calculations, and dosed to get back to 1300ppm MG. I tested again 24 hours later, and I was exactly at 1300ppm. The next several weeks my MG never dropped, and by 11/5 it was up to 1320.

On 11/14 it measured 1420, so, thinking my test kit might be bad, I tested with my NYOS Kit and it measured 1400. I measured last night, and my MG is now at 1460. I haven't dosed Ions since 10/12, and I can't figure out what is going on.

My normal levels are very steady (Thanks to the Neptune DOS) at:
Alk=9.5
Calcium=450
MG=1300

Now I did have an issue around 11/8 where some Ca got spilled into my sump. My Alk dropped to 8.68 and my Calcium went up to 470. My assumption is that the extra Ca precipitated out the Alk, but I wouldn't think that would cause my Mg issues. Plus it was rising before that.

i am not dosing anything else, and I haven't done a water change during this stretch, and I am only feeding frozen food. Nothing else goes in the tank.

Any ideas as to what could be going on? I feel like I have a basic understanding of the Alk/Ca/Mg relationship, but not enough to understand what is going on. Any help is greatly appreciated.
 

bertoni

Premium Member
Magnesium can't rise without something being added to the water column. I can't think of many credible possibilities. What is being dosed for calcium and alkalinity?
 

pisanoal

Premium Member
Magnesium can't rise without something being added to the water column. I can't think of many credible possibilities. What is being dosed for calcium and alkalinity?

Looks like Seachem Reef Fusion which do have "biological equivalents" of NSW elements.

What is your water change regiment, and what salt? Your salt could be very high in Mg and consumption might not be enough to keep up with WC's and dosing.
 

bertoni

Premium Member
I have no idea exactly what they mean by "biological equivalents" in this context, but if the supplements don't have magnesium in them, they won't raise magnesium.
 

tklb

New member
Reef Fusion 1 & 2 are the only thing I am dosing. No water changes during this time span. I use Reef Crystals.

I agree no reason it should be rising, but 2 different test kits (Red Sea & NYOS) show it rising. Any other ideas? I am stumped.
 

bertoni

Premium Member
I am very puzzled. I might try buying a bit of plain calcium chloride, to see whether the batch of Reef Fusion might have a problem, but I would be surprised if that were the case.
 

Walla2GSP

New member
I am very puzzled. I might try buying a bit of plain calcium chloride, to see whether the batch of Reef Fusion might have a problem, but I would be surprised if that were the case.

or mix 1 gallon of fresh saltwater, test mg; add 2 Tsp Fusion 1, test mg ; add 2 Tsp Fusion 2, test Mg; and compare the results to see if any of the above contain higher than usual amounts of Mag.
 

Rybren

Active member
I'm inclined to think that the issue relates to testing: a bad test kit, improper procedures for testing, the "noise" level of the test kit, or a combination of the 3.
 

Oldmansanders

New member
Reed fusion 1 (the calcium part) has magnesium in it. They say that it contains the right amount to keep it steady with the consumption of CA/ALK so theoretically it shouldn't be rising while the other Paramus stay stable. Maybe Ca/ALK are precipitating and not being used to build skeletons. Either way, if you're using reef fusion, you are putting magnesium in the tank.
 

bertoni

Premium Member
Under 1300 ppm to 1460 ppm is quite a lot of test error, but it's possible. I think it'd be odd for two test kits to fail in this way, though.
 
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