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How important is Magnesium?


Crazy Tiki

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Hey Guys, just wanted your feedback on Magnesium dosing, as I got an ear full on two different views.

 

I have a BC14 and do a 1.5 gallon water change each week. I also have Chemipure Elite, Purigen and a Purapad as my chemical filtration. I have a API reef test kit that tests Nitrates, Phospates, KH and Calcium. My calcium is normally in the area of 380-400 and KH is 8 and Nitrates and Phosphates are zero.

 

Two weeks ago I got two montipora frags and wanted to raise the calcium level to ensure their growth, so I purchased some ESV Bionic - 2 part to help supplement. So I decided to dose according to the bottles 2.5 ml for the first two days(calcium=380, alk = 9 before supplementing), then 5 ml on the third and 7.5 on the fourth(calcium= 400, alklinity=11 before supplementing).

 

In reading and talking to a couple of people when dosing the Bionic they told me to watch my PH, so I went to the fish store to get a PH test kit and in talking to them they told me to actually watch my magnesium. I ended up taking a sample to them to test and found my MG was at 1050ppm (normal level 1200) So I ended up purchasing a MG test kit and the ESV Mg supplement.

 

I haven't heard of MG being an issue for most people and since I do weekly water changes didn't know why it would be below normal levels. The only thing I can think of is the Purigen and Purapad, so will go home today and remove the Purapad, but also wanted to hear your thoughts on Magnesium as another fish store just told me to watch my Calc and Alklinity and that he never tested for Mg.

 

Thanks for you help

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also low mg can lead to byropis which is GHA like but does not like high mg levels. i currently have some and doing my best to get rid of it.

 

not only this but low mg can make it more difficult to maintain Ca.

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FiRsT-aNd-LaSt
I doubt purigen and/or puripad is affecting your MG levels. Maybe the water you're adding is low? Have you tested the new salt water?

+1 my guess would be the new salt isn't supplying as much, usually with regular weekly water changes it should stay in range, I never dose and my MG stay's steady at 1350ppm. As far as how important, IMO it's not something to be super concerned about, but if the levels do get low, you'll usually have problems keeping your ALK and Cal stable, all three go hand in hand.

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I buy premixed water from my lfs store, will have to get you guys the brand but I know its not anything cheap like instant ocean

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nanoreefnate

Is the store your talking about Neptunes?

and have i met you before?

 

I worked there over the summer...=P

 

the only reason i would think of Neps is because they're always concerned about Mg

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I get my dosing chemicals at bulkreefsupply which cost less than bionic. You are suppose to get your magnesium up to par before you dose calcium and alk two part. I know that all 3 must be in balance for it to work. I even dose strontium as that is required by most sps.

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Mg is only important if it is way off, imo.

 

Aim for NSW levels, and don't worry too much about it. Very low Mg can make it difficult to maintain adequate Ca levels, and very high levels can also cause problems, but this is less common.

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Mr. Thingdoer
I get my dosing chemicals at bulkreefsupply which cost less than bionic. You are suppose to get your magnesium up to par before you dose calcium and alk two part. I know that all 3 must be in balance for it to work. I even dose strontium as that is required by most sps.

 

NEVER DOSE STRONTIUM!

it "poisons” calcium ion transport across coral epithelial tissues

 

 

quoted from

 

Chemical Supplements

 

By Ronald L. Shimek, Ph. D.

 

"The story starts about sixty years ago, shortly after the first American hydrogen bomb tests, which were done on Pacific atolls in the early 1950s. The thermonuclear reactions of such explosions transmuted some of the calcium in the vaporized atoll limestone into an isotope of strontium, strontium90. Strontium90 soon became important because, like all other strontium isotopes it behaves similar to calcium and in that regard it soon became apparent it was being deposited in human bones. It is also highly radioactive and quite dangerous. As a result of these two facts, the human usage and the radioactivity, a widespread program of testing for strontium in the natural world was initiated. One of the more interesting facts that came from this was the information that strontium, of all isotopes, was deposited in small amounts in coral skeletons. The second fact of interest was that this deposition of strontium in coral skeletons was related to temperature, so there was a minor, but widespread, survey of corals and fossil corals to measure the amount of strontium. In this way, it became possible for paleontologists to estimate the temperature of ancient seas. If the strontium was being deposited the same way in ancient times as it was being deposited today, and if there was a temperature relationship, then one could assume what happened then was similar to what was happening now and make a guess as to the ancient seas’ temperatures.

 

Well, the tale wasn’t as simple as it first appeared. It was presumed that strontium being just slightly larger than calcium was being used in chemical reactions, “by happenstance” or mistake, at about the relative proportional abundance of strontium to calcium. That was the state of the art in the early 1980s. In the late 1970s, a student working at a site in the Great Barrier Reef did an experiment where he incubated corals with an excess of strontium in solution. By golly, he got good, and extra, coral growth in the skeleton. And he published this in 1980 (Swart, 1980). The conclusion was that extra strontium in solution boosted coral growth. A few years later this was noticed by some coral reef aquarists and they incorporated that information into some publications (Delbeek, and Sprung, 1994).

 

Unfortunately, what those reef aquarium authors didn’t do was read the next article that the initial researcher wrote (Swart, 1981). Here he explained that his first conclusion was an error. What had happened was that in the region where he did his research, the sea water concentration of calcium was only about 310 ppm, and any material similar to calcium - including – Golly, Gee, Surprise, Calcium itself, added to the sea water would increase the growth of corals. So the data saying that strontium was causing extra growth in corals was in error. What was happening was that anything like calcium (including calcium, magnesium and strontium) added to the sea water of that area would increase coral growth, up to a maximum level of about 525 ppm, after which the increase in growth ceased. Of course our stalwart aquarium authors (Delbeek, and Sprung. 1994) never bothered to get the message…

 

But, as they say, “That ain’t all…”

 

Other researchers, more interested in how strontium was added to the coral skeleton, found some very neat things. They found that strontium is incorporated into the coral skeleton differently than is calcium. It doesn’t simply replace calcium in the aragonite crystal lattice (Chalker, 1981; Ip, and Krishnaveni. 1991). This means that there is a special biochemical process or pathway in corals to ensure that strontium is put into the coral skeleton.

 

The question any scientist – and aquarist – interesting in strontium should ask themselves is, “Why is strontium deposited differently than is calcium?” The answer to that question was found by two other researchers (Wright and Marshall, 1991). These scientists found that strontium inhibits or “poisons” calcium ion transport across coral epithelial tissues. This very important and bears repeating:

---

“Strontium “poisons” calcium ion transport across coral epithelial tissues.”

---

 

Why is this important? The answer is that calcium is very important to corals. One might think that it is most important in that it goes to form the skeleton, but that is probably a secondary issue. What is more important is that calcium is used and found in high concentration in the nematocysts that corals use to catch their food. Additionally, calcium is important in the relaxation and resetting of the coral animal’s muscles. Once the muscle contracts, unless there is an excess of calcium ion in the coral’s epithelium, that muscle cannot relax and reset itself to contract again and the animal can’t move.

 

The final piece to this puzzle of strontium is that strontium is deposited in coral skeletons as a specialized mineral called Strontianite (Greegor, et al. 1997).

 

The whole strontium story with regard to corals is that strontium is a weak poison, inhibiting the transfer of calcium into the coral’s tissues and thus affecting all of the biology of the coral. Because of this, natural selection has favored a process to remove strontium from its tissues. The way in which the coral does this is by specifically depositing strontium as a special mineral in small clusters in its skeleton. Once the strontium is precipitated as a mineral it is out of solution and no longer a threat to the coral’s metabolism. Ideally, for a coral, its sea water would not have an excess of strontium, but it would strontium-free.

 

Consequently, it is to the advantage of a reef aquarist to NEVER add any material containing strontium to their system.

 

And, of course, most stalwart aquarium authors never bother to get the message…"

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Is the store your talking about Neptunes?

and have i met you before?

 

I worked there over the summer...=P

 

the only reason i would think of Neps is because they're always concerned about Mg

 

Yeah, I was talking to Robert and his wife (never got her name) as she has a BC14 (which she has a claim, a couple of chalices and acans with stock lighting) and I asked her about dosing which is what lead me on this journey.

 

Based on my brief research on Mg everything they informed me was correct, but in talking to other reefers they seemed to not really think it was that important. I dosed 15ml of the E.S.V. magnesium today and will do a 3 gallon water change, which will hopefully also bring up the MG level so that I don't have to dose MG for the whole month.

 

SPS20: I believe the LFS used a Salefiet test kit and then I also bought one.

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Well Guys, just wanted to give an update. Did a 3 gallon water change on Tuesday evening and tested parms on Wednesday morning.

 

Nitrate = 0, Phosphate = 0, Calcium = 400ppm, KH = 10, Mg = 1100

 

The water I purchase premixed from LFS and they use Reef Crystals which is supposed to have a Mg of 1300.

 

Everything is doing fine, so I guess I will just keep dosing Mg for a couple of more weeks just to get it up.

 

thanks for the help.

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  • 3 weeks later...

I never had problems with MG levels until now, as it appears. The Ca level has dropped with an imbalance of Kh. My tank is well seasoned, 3 plus years. I have only had this problem occur recently, which is due to maximum capacity of coraline, coral, and microlifes. So I would not be too concerned with a new tank on Magnesium levels, however, if your tank is blooming like mine, keep a check on you Mg levels, or it will creep up on you and LPS's are the first to go.

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I never had problems with MG levels until now, as it appears. The Ca level has dropped with an imbalance of Kh. My tank is well seasoned, 3 plus years. I have only had this problem occur recently, which is due to maximum capacity of coraline, coral, and microlifes. So I would not be too concerned with a new tank on Magnesium levels, however, if your tank is blooming like mine, keep a check on you Mg levels, or it will creep up on you and LPS's are the first to go.

 

I have noticed a lot of coraline and coral growth over the last month and I attribute that to sucking up the MG. I had been dosing 15ml of E.S.V. MG a day and it only raised my MG level by 50 ppm per week. For the last week I have increased the dose to 25ml in hopes to finally get it up to 1200ppm. - As a note to everyone when dosing MG please check your Salinity as it will rise. Doing a water change on tuesday and testing Wednesday will post results later this week.

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