Oops! Ultra low magnesium. My observations

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So most of my corals have been doing great, but several havent been too happy. For example, if they get injured, they heal slowly or dont heal at all. Also, growth has been slower than usual for most of the corals.

After the recent post, i realized i hadnt tested my Mg in over a year! Maybe partially attributed to work stress, buying a new house, and other responsibilities that ramped up quickly. Combined with minimal water changes, and half-the-time i used inferior quality salt. All-in-all, it was being utilized faster than it was being replaced over a long period of time.

Tested my Mg.... ultra ultra low, <200ppm (perhaps ~170ppm ish). ... so i did a 30% water change, and added extra MgSO4. I will supplement heavily daily for the next 2 weeks to bring it up, and boost my dosing.

Meanwhile, there have been numerous interesting observations recently:

1) Montipora setosa seemed to grow at normal rate, and was completely unaffected. Perhaps suggesting it has a lower Mg requirement than most other corals. Other corals also seemed unaffected. But the setosa was surprising.

2) Leptoseris turned brown from the inside of the colony spreading outward. But not entirely.

3) Trachyphylia, Micromussa lordhowensis, *some* euphyllia, and 2 of my favias seemed strongly affected. Deteriorating slowly, and unable to recover.

4) 8 of my 10 different euphyllia seemed fine. Fortunately, all the best ones.

5) Deepwater smooth acros seemed unaffected. With minimal affects on other acros, mostly just super slow growth.

6) Monti Caps didnt grow hardly at all. Super weird.

7) Acanthophylia (meat coral) and Lobophylia seemed moderately affected. They grew and healed fine, but slower than expected.

8) Utter Chaos also grew super slowly. Blue hornets died off i think. All other zoas and palys (and gsp) grew, just slightly slowly.

9) Still tons of coralline.

10) The one bta anemone hasnt split all year. Still growing slowly, and quite big though.

Thats all for now. Thought yall may be interested in the observations.
 
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I would be very skeptical of that test result. I would retest with a different kit.
Thats fair.

After the water change and adding several kg of MgSO4 over the past few days, my Mg is now 1000 (using a different kit).
 
That's exactly what I was thinking. While the coral will uptake a little Mag, it's more of a buffer for cal. Really interested in how the numbers for cal & alk looked during the last year, especially at the end.
 
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Randy Holmes-Farley wrote a great article which speaks to this & within the article illustrates why? -

“Often the inability to maintain adequate calcium and alkalinity despite extensive supplementation, and the precipitation of significant amounts of calcium carbonate on heaters and pumps, are signs that the water has inadequate magnesium.”

 
Randy Holmes-Farley wrote a great article which speaks to this & within the article illustrates why? -

“Often the inability to maintain adequate calcium and alkalinity despite extensive supplementation, and the precipitation of significant amounts of calcium carbonate on heaters and pumps, are signs that the water has inadequate magnesium.”

Exactly, low Mag will result in precipitation. Down at the level of 100~800 I'd be surprised if the water could hold any Cal at all.
 
Alk and calc have been mildly low, but within acceptable range, while ive been ramping up dosing.

Specific numbers are recorded in my notebook at home. But from memory, Calcium was low 400s, and alk dkH was low 8's.

And yes, i had precipitation on heaters and pumps.
 
I can type up my handwritten test results for you guys, and post photos of the precipitation on the heater if yall find want. No problem!
 
That is insane. I'm sure you know what you're doing, but I never heard of Mg dropping that low without everything else going out of whack.

Yeah, i was shocked at how much i was dosing, without seeing corresponding growth, nor corresponding increases in calc and alk. I just kept increasing and increasing dosages.

Its an imperceptible amount short-term... but over the course of many months, it becomes noticable.

And yeah, lol. My job entails mixing various compounds in a chemistry lab, elemental analysis, and graphing and writing about my findings.... speaking of, i am submitting my first paper for publishing (Journal of Resources, Conservation, and Recycling). The draft is finalized, has been reviewed and edited, and is being reviewed 1 more time before submission. Woohoo!
 
Yeah, i was shocked at how much i was dosing, without seeing corresponding growth, nor corresponding increases in calc and alk. I just kept increasing and increasing dosages.

Its an imperceptible amount short-term... but over the course of many months, it becomes noticable.

And yeah, lol. My job entails mixing various compounds in a chemistry lab, elemental analysis, and graphing and writing about my findings.... speaking of, i am submitting my first paper for publishing (Journal of Resources, Conservation, and Recycling). The draft is finalized, has been reviewed and edited, and is being reviewed 1 more time before submission. Woohoo!
The dosing increase makes sense. I've never run across someone getting that low on mag. I'm shocked you were even able to keep the Alk and Cal up with virtually no Mag in the system. Best of luck getting it all balanced up again.
 
Pardon the delay. Busy week so far.

I typed up my book... just since jan 1st. For those curious, here are my calc and alk. Left axis is Alk, dkh. Right is Calc, ppm.

Lowest dips correspond to water changes.

20221108_150243.jpg
 
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Just curious, but how old were the Mg reagents you used?
One of them was well past due (Red Sea part C, 2019 i think). But thats why i often use two sets of test kits of varying ages.

Once again, i'll have to wait until im home to get specifics and check all reagent ages.
 
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