magnesium uptake in sps tank
 

Just wonder how fast will an sps tank deplete its magnesium??

because I am starting think that the media I used in my calcium reactor doesn't put out enough magnesium(arm media),

http://www.jlaquatics.com/product/cr...8-10+lbs..html

any thoughts??

thanks

Not nearly as quickly as it will consume calcium and alkalinity. Water changes might be able to keep up. If not, the cheapest way to boost it is to use magnesium salts.

I can't remember the exact number but there is data on reef central saying its something like 1ppm for every 20ppm of calcium. I am guessing but it is close to that. Let me know if you find it again i'm also curious.

I use the same media and every month or so I have to add 1/4 to 1/2 cup of Epsom salts to keep my Mg level up.

mag rock
 

jl also sells zeovit mag roc that i put in my cal. reactor at 10% like recomended and it sure helps me

mag
 

IME, once your tank is stable and assuming all 3 levels are near NSW, magnesium will deplete at a rate of 1:2 in reference to CA and ALK. In my tank, the magnesium is the most stable element of the three, it's solid. As for the Zeo Mag, I think this product is junk unless you have a CA reactor and willing to measure it constantly. Better off using mag in bulk chem for accuracy and economically.

ARM's new mix is "high magnesium" but still not perfect. I dose extra on water changes with Randy's DIY recipie. Apperently Dolomite(Dolcimite?) in the calc reactor works, people have been using that for a long time.

Check salt mixes too, i use IO and it's low. Just bringing it up to 1300 at water changes keeps my tank balanced at about 1200-1250.

The rate of magnesium consumption in every tank is different because of different critters we have in our tanks. IME and from reading a lot of articles and posts, magnesium depletion rate should be very slow if you keep up with regular water change with a salt that has good magnesium number.
Here is an article on magnesium from Randy HOLMES-FARLEY

http://www.advancedaquarist.com/issues/oct2003/chem.htm

I think the magnemsum depletion rate in your tank depends on your setup. Mine for example, before i have lots of mangroves which consume lots of Mg , so now i took them out and the depletion rate has been dramatically decrease. The best way is bring your Mg to the desired level and then measure again in a day or week then you know how much Mg is consuming by your tank.

Good luck

I am thinking using some of these when I have to refill calcium reactor. at the mean time probably keep on dosing.
http://www.jlaquatics.com/product/bw...ia+-+1+KG.html

so, plants/macro algae uses more magnesium than coral then??

thanks

I've been running my sps tank for a year and a half and I've dumped about 100 lbs of magnesium into the tank. That seems like a lot to me. I run zeomag in my calcium reactor along with ARM? I don't know why. This is just from experience. I use Littlesilvermax's Mg mix.

I agree, I have to dose a lot of it to keep up with the demand. I even try to keep the coraline algae to a minimum because it can be a big sink for mag.