Any way to reduce Magnesium

[John May]

and i use LED lights with 25% white 100% blue

 

[Randy Holmes-Farley]

i use the salifert mag test kit. I discovered that the elevated levels are due to the salt that I use. However, alot of my corals have been closing up more. My mg is 1600 as i mentioned, calc is 420, ph is 8.4, ammonia nitrate and nitrate all pretty low. Any ideas? Alk is around 8 also

I don't expect they are closed up due to the magneisum, but the only way to lower it is to switch to a lower magnesium mix for water changes.

 

[NewarkFrags]

Sorry for the opening of an old thread but I have the same issue all my levels are stable but mag is high at 1600 will not move CA KH PH are all in the perfect range. I use the red sea coral pro salt and have decided to try and reduce the level by doing less water changes as I am guessing the MG is not being consumed by the tank as fast as the CA & KH I will post my findings.

 

[Dr. Reef]

mag at 1600 is not high in my opinion. Mag has a very wide acceptable range. as low as 900 to as high as 2100. People keep mag at 2100-2300 to fight off algae. Most common window is 1300-1600 and almost all the reef salts that i have used and some i know off mix mag within this window of 1300-1600.
i wouldnt do anything to reduce it.

 

[Drewbacca]

Same problem, I have NEVER once dosed magnesium...only brs kalk and have muliple 1560 readings on both red sea and salifert. I also have an issue with sand hardening where return shoots down. (Like half inch thick 3x5 area that wont budge off glass or chip) I use red sea pro salt, but thats still only 1350 if I did 100% new sw.
STUMPED
Thinking of changing to core 7 or 2 part to see if it helps.

 

[Keen4]

Mangroves will do the trick.

Really?> Mangroves will take up the magnesium? My reef tank is cycling and I tested the magnesium today and I got a 1440 ppm with the salifert test kit.

 

[Keen4]

Same problem, I have NEVER once dosed magnesium...only brs kalk and have muliple 1560 readings on both red sea and salifert. I also have an issue with sand hardening where return shoots down. (Like half inch thick 3x5 area that wont budge off glass or chip) I use red sea pro salt, but thats still only 1350 if I did 100% new sw.
STUMPED
Thinking of changing to core 7 or 2 part to see if it helps.

I use the same salt and I get a high mg reading also.

 

[Randy Holmes-Farley]

Really?> Mangroves will take up the magnesium? My reef tank is cycling and I tested the magnesium today and I got a 1440 ppm with the salifert test kit.

Mangroves are not a particularly useful tool to reduce elevated magnesium, IMO. As shown below, it takes a large amount of plant matter to make a dent in magnesium.

This paper shows that content of seedling mangroves of a particular species grown in seawater of different concentrations. Relative to sodium and chloride, the plant material itself is not enriched in magnesium relative to sodium, and the levels are so small that the content of the plant is equivalent to about 1.3 to 3.3xin seawater. Thus, one pound of mangrove tissue contains about the same amount of sodium s as 2 pounds of seawater and the same amount of magnesium as 1.3 to 3.3 pounds of seawater. Thus, there is no great concentrating mechanism in the plant.

https://www.jstage.jst.go.jp/article/tropics/5/1+2/5_1+2_69/_pdf/-char/en

As the mangroves get older, magnesium in leaves can rise somewhat. This paper shows that one mL of the oldest leaves with the highest magnesium concentration contains 802 micromoles per mL of water in the leaves/

https://www.publish.csiro.au/bi/pdf/BI9670589

802 micromoles equals 19,500 micrograms = 19.5 mg of magneisum per mL of water in the leaf

That's hardly enriched at all relative to seawater that contains 13 mg per mL.

Let's suppose you want to remove 50 ppm of magnesium from 100 gallons (378 L) of seawater. That means you want to remove 50 mg/L x 378 L = 18,500 mg.

How much plant material does that take?

It takes more than a kilogram of plant material.

That kilogram will also be taking out sodium and chloride, thus its efficiency at selectively removing magnesium is much less than calculated.

 

[Keen4]

Mangroves are not a particularly useful tool to reduce elevated magnesium, IMO. As shown below, it takes a large amount of plant matter to make a dent in magnesium.

This paper shows that content of seedling mangroves of a particular species grown in seawater of different concentrations. Relative to sodium and chloride, the plant material itself is not enriched in magnesium relative to sodium, and the levels are so small that the content of the plant is equivalent to about 1.3 to 3.3xin seawater. Thus, one pound of mangrove tissue contains about the same amount of sodium s as 2 pounds of seawater and the same amount of magnesium as 1.3 to 3.3 pounds of seawater. Thus, there is no great concentrating mechanism in the plant.

https://www.jstage.jst.go.jp/article/tropics/5/1+2/5_1+2_69/_pdf/-char/en

As the mangroves get older, magnesium in leaves can rise somewhat. This paper shows that one mL of the oldest leaves with the highest magnesium concentration contains 802 micromoles per mL of water in the leaves/

https://www.publish.csiro.au/bi/pdf/BI9670589

802 micromoles equals 19,500 micrograms = 19.5 mg of magneisum per mL of water in the leaf

That's hardly enriched at all relative to seawater that contains 13 mg per mL.

Let's suppose you want to remove 50 ppm of magnesium from 100 gallons (378 L) of seawater. That means you want to remove 50 mg/L x 378 L = 18,500 mg.

How much plant material does that take?

It takes more than a kilogram of plant material.

That kilogram will also be taking out sodium and chloride, thus its efficiency at selectively removing magnesium is much less than calculated.

This is an awesome post- Thank your the clarification and deep education! well put. Besides- what are we to do when the mangroves outgrow the sump!? They grow so large!!!

 

[garyd18166]

hi all my Mag is the same 1500 never dosed it and the salt i use is AF

 

[garyd18166]

Hi all.. i am totally new to this hobby and i love it.
I also am trying to balance all my prams, but for the life of me Mag is 1500 and has never dropped , my salt is Aqua forest and all my other prams are doing ok, although i have just had a outbreak of GHA..

 

[((FORDTECH))]

Hello I have mag at 1520 in 2 different 300 gallon systems tested with there own trident. I do not dose any mag at all. I do daily 3.5 gallon water changes with reef crystals. Tested fresh mixed salt and get 1550 mag

 

[Randy Holmes-Farley]

hi all my Mag is the same 1500 never dosed it and the salt i use is AF

Of course, that is just a kit result, and it may be off. Your salinity may also be higher than you think. Magnesium testing is prone to big errors, and the Red Sea kit gives more trouble than most.

 

[Randy Holmes-Farley]

Hello I have mag at 1520 in 2 different 300 gallon systems tested with there own trident. I do not dose any mag at all. I do daily 3.5 gallon water changes with reef crystals. Tested fresh mixed salt and get 1550 mag

IMO, high salinity or faulty testing is more likely than magnesium actually that high at 35 ppt. But any of them may be true.

 

[((FORDTECH))]

IMO, high salinity or faulty testing is more likely than magnesium actually that high at 35 ppt. But any of them may be true.

I salinity is 35 in both of my 300 gallon systems. And I have cross checked magnesium with both of My tridents Testing each other’s water and both testing freshly mixed salt water. So I know it’s not a salinity issue and then there’s the obvious is trident not accurate but I literally have two of them testing the same thing

 

[brandon0921]

Hey @Randy Holmes-Farley
My magnesium has been slowly rising in my acropora dominated tank for the past 6 months or so. I’ve been getting readings of 1500-1600 2x daily on the trident and confirmation of those numbers via ATI ICP tests on a monthly basis. I use a calcium reactor with ARM coarse media, dose easysps, easy booster (food), use moonshiner trace elements, and have not performed a water change in over a year. Subsequently, my calcium has been constantly dropping which I have been supplementing with brightwells calcium product. I haven’t noticed any ill effects in the tank and I’m wondering if there should be any concern if magnesium levels continue to rise?
Thanks in advance,
Brandon

 

[Randy Holmes-Farley]

Hey @Randy Holmes-Farley
My magnesium has been slowly rising in my acropora dominated tank for the past 6 months or so. I’ve been getting readings of 1500-1600 2x daily on the trident and confirmation of those numbers via ATI ICP tests on a monthly basis. I use a calcium reactor with ARM coarse media, dose easysps, easy booster (food), use moonshiner trace elements, and have not performed a water change in over a year. Subsequently, my calcium has been constantly dropping which I have been supplementing with brightwells calcium product. I haven’t noticed any ill effects in the tank and I’m wondering if there should be any concern if magnesium levels continue to rise?
Thanks in advance,
Brandon

I personally wouldn't want it much higher. Snails become lethargic.

Maybe the media has more magnesium than your tank is consuming. The fact the calcium is dropping at stable alk also suggests this.

 

[homin009]

There are 2 ways you can do that. 1. Change the existing water and 2. Use Calcium Hydroxide.
To learn more you can read this article that may help https://aquifarm.com/how-to-lower-magnesium-in-reef-tank/

 

[Randy Holmes-Farley]

There are 2 ways you can do that. 1. Change the existing water and 2. Use Calcium Hydroxide.
To learn more you can read this article that may help https://aquifarm.com/how-to-lower-magnesium-in-reef-tank/

Welcome to reef2Reef!

Have you ever tried the method in that article? I'd be concerned about more happening than it says if you run seawater through a calcium hydroxide reactor. Removal of a variety of trace elements and phosphate, precipitation of calcium carbonate, a VERY substantial pH rise, etc.