Magnesium continues to increase without supplementation.

Randy Holmes-Farley

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Okay, the quick google tells me STAX are mined limestone Oolite
Wikipedia tells me Oolite (for egg) is sedimentary rock formed from concentric spheric layers of (in no particular order) phosphate, clay, chert, DOLOMITE, or iron minerals.
Yes the same dolomite (Calcium Magnesium Carbonate) we often use in calcium reactors for Mg addition.
But at tank pH my guess would be that the Mg addition from quarried limestone is minimal?
Thoughts?

Dolomite can not explain the result because alk would be rising a huge amount. This is from one of my articles:

It has been suggested that adding dolomite to CaCO3/CO2 reactors can help with magnesium problems. Dolomite is a material that contains both magnesium and calcium carbonate. If dolomite is being added to the reactor to maintain existing appropriate magnesium levels against the continual depletion via calcification (for example, if the calcium carbonate being used is too low in magnesium to maintain adequate magnesium) then this is a fine approach.

However, this method is unsuitable if the goal is to raise magnesium levels. The problem is that for every magnesium ion released from the dolomite, 2 units of alkalinity are also released:

MgCO3 → Mg2+ + CO32-

Consequently, if one wants to raise magnesium by 100 ppm, the alkalinity will necessarily rise by 8.2 meq/L (23 dKH). The only way around this problem is to add a mineral acid (not vinegar) to the aquarium to reduce the alkalinity, and that may be more problematic than just adding magnesium in the first place.
 

Randy Holmes-Farley

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So pushing calcium up 100 ppm with ESV doesn't seem to change magnesium. It reads 1420 still.



My sand is also Oolite...
Ok, so it is not the salt mix or the ESV supplement.
 

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Dolomite can not explain the result because alk would be rising a huge amount. This is from one of my articles:

It has been suggested that adding dolomite to CaCO3/CO2 reactors can help with magnesium problems. Dolomite is a material that contains both magnesium and calcium carbonate. If dolomite is being added to the reactor to maintain existing appropriate magnesium levels against the continual depletion via calcification (for example, if the calcium carbonate being used is too low in magnesium to maintain adequate magnesium) then this is a fine approach.

However, this method is unsuitable if the goal is to raise magnesium levels. The problem is that for every magnesium ion released from the dolomite, 2 units of alkalinity are also released:

MgCO3 → Mg2+ + CO32-

Consequently, if one wants to raise magnesium by 100 ppm, the alkalinity will necessarily rise by 8.2 meq/L (23 dKH). The only way around this problem is to add a mineral acid (not vinegar) to the aquarium to reduce the alkalinity, and that may be more problematic than just adding magnesium in the first place.
Thanks :)
It's never as easy as it seems.
 
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tankstudy

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Magnesium has reached 1700 today and alk has dropped to 7.3 dkh.

Are there any type of items that can leach magnesium? Like metal parts, magnets or certain objects?
 

Randy Holmes-Farley

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Magnesium has reached 1700 today and alk has dropped to 7.3 dkh.

Are there any type of items that can leach magnesium? Like metal parts, magnets or certain objects?
Nope. Even if you had a metal item that was mostly magnesium and corroding, the alkalinity would go through the roof.
 
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tankstudy

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have you checked your top off water with the kit?

Not yet. I'd still have to order a test kit for freshwater, unless the salifert or redsea one works but when I looked at them they were specifically for saltwater I believe.
 

Randy Holmes-Farley

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Not yet. I'd still have to order a test kit for freshwater, unless the salifert or redsea one works but when I looked at them they were specifically for saltwater I believe.

I would try one of them.
 
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Using both kits, and doing each twice, the results appear to be all zero.
 
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Is there a possibility that my tank can out consume the alkalinity being produced by the breakdown of dolomite?

With an increase of 20 ppm magnesium since monday, that would be about 4.6 dkh? With a release over a period of 2-3 days or maybe even 3-4 days since I don't know the exact date that magnesium hit 1680 ppm?

The inhabitants of this tank came from my previous tank which was consuming 1.2-1.7 dkh per day.
 

Randy Holmes-Farley

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Is there a possibility that my tank can out consume the alkalinity being produced by the breakdown of dolomite?

With an increase of 20 ppm magnesium since monday, that would be about 4.6 dkh? With a release over a period of 2-3 days or maybe even 3-4 days since I don't know the exact date that magnesium hit 1680 ppm?

The inhabitants of this tank came from my previous tank which was consuming 1.2-1.7 dkh per day.

Tanks don’t use large amounts of alk except by calcification, which drops calcium. In that theoretical mechanism, calcium would be dropping more than magnesium is rising.
 

KenRexford

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I posted the same strange increase recently myself. I have been thinking...

Barring a microscopic black hole going micro-nova in our tanks, magnesium is not just being created. If it is also not being added, then the only remaining option, if the tests are right, is that the magnesium was already in the tank but not in the water. Maybe rock/sand leaching, maybe calcareous algae leaching, or maybe corals leaching.

My untrained mind leads me to the possibility that added calcium from two-part is somehow trading places with the magnesium. Suppose, for example, that a calcium compound is somehow more stable than a similar magnesium compound. Add in stray voltage and maybe the calcium ions kick out tge magnesium back into the water.

Or, maybe the power source is biology. Imagine low calcium causing fast grown corals to grab abnormally high magnesium as a temporary fix. You then test parameters and find calcium drifted low. So, dump calcium and fix. The corals sigh with relief and start replacing the duct-tape-magnesium with the new calcium, thereby releasing the magnesium back into the water.

Just an uneducated thought.
 

Randy Holmes-Farley

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I posted the same strange increase recently myself. I have been thinking...

Barring a microscopic black hole going micro-nova in our tanks, magnesium is not just being created. If it is also not being added, then the only remaining option, if the tests are right, is that the magnesium was already in the tank but not in the water. Maybe rock/sand leaching, maybe calcareous algae leaching, or maybe corals leaching.

My untrained mind leads me to the possibility that added calcium from two-part is somehow trading places with the magnesium. Suppose, for example, that a calcium compound is somehow more stable than a similar magnesium compound. Add in stray voltage and maybe the calcium ions kick out tge magnesium back into the water.

Or, maybe the power source is biology. Imagine low calcium causing fast grown corals to grab abnormally high magnesium as a temporary fix. You then test parameters and find calcium drifted low. So, dump calcium and fix. The corals sigh with relief and start replacing the duct-tape-magnesium with the new calcium, thereby releasing the magnesium back into the water.

Just an uneducated thought.

I cannot see that scenario happening from a chemistry or biology standpoint. Sorry lol
 
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tankstudy

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I'm guessing the one thing we can sort of conclude is that magnesium is climbing but the source of it is unknown?

Similar to how we were slowly eliminating possible factors, I was thinking of slowly eliminating things, equipment or anything, in my tank as I do these bandaid water changes.

It's going to take a long time but maybe I'll figure it out eventually?
 

Randy Holmes-Farley

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I'm guessing the one thing we can sort of conclude is that magnesium is climbing but the source of it is unknown?

Similar to how we were slowly eliminating possible factors, I was thinking of slowly eliminating things, equipment or anything, in my tank as I do these bandaid water changes.

It's going to take a long time but maybe I'll figure it out eventually?

I’m not 100% convinced it is rising. I know the folks are convinced, but unless they are adding it, it is not rising and magnesium test issues are VERY common.
 

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