Magnesium

Chris Adams · Jun 24, 2015

My tank is 30gl mixed with mostly SPS. Magnesium lingers around 1280.

What is your Magnesium level
If you dose what product do you use

Is there an ideal for SPS or is 1250 - 1500 just a range to shoot for?

saltyphish · Jun 25, 2015

I try to run mine at 1350. Bulk reef supply has calculators and the mag you dose. I believe it is actually soda ash. I don't dose so don't quote me even though I know I have a bottle of it around.

jeremy · Jun 25, 2015

Soda ash off of bulk reef supply is the alkalinity supplement. They do have a handy calculator for figuring corrections. I run my magnesium around 1400. 1280 is fine.

redfishbluefish · Jun 25, 2015

Actually your home made MAG solution should be magnesium chloride and magnesium sulfate (Epsom salt). The soda ash (sodium carbonate) is used to make your ALK solution. BRS is a good place to purchase the DIY chemicals. And finally, 1280 is a good number for MAG.

Randy Holmes-Farley · Jun 25, 2015

Chris Adams said:
My tank is 30gl mixed with mostly SPS. Magnesium lingers around 1280.

What is your Magnesium level
If you dose what product do you use

Is there an ideal for SPS or is 1250 - 1500 just a range to shoot for?

Your value almost exactly matches the ocean average (~1285 ppm for typical 35 ppt seawater) and there's no reason to change it, IMO.

That said, raising it is fine if you want, but I would not intentionally plan to keep it above 1400 ppm. I would use a DIY per the recipe in the second article (which is now sold by a variety of suppliers such as BRS):

These have more:

http://www.advancedaquarist.com/2003/10/chemistry

http://reefkeeping.com/issues/2006-07/rhf/index.php

Chris Adams · Jun 25, 2015

ok thanks everyone. So far kalk has been all I need to keep the #'s stable along with weekly 5gl WC.
Mag did drop from 1400 range to current levels after starting kalk a few months back and someone had mentioned to keep an eye on it.

Randy Holmes-Farley · Jun 26, 2015

Yes, it is worth keeping an eye one.

I too use just limewater for my system.

Chris Adams · Jun 26, 2015

Thanks Randy.

Randy Holmes-Farley · Jun 26, 2015

You're welcome.

FWIW, magnesium depletion is typically on the order of 0.1-2 ppm daily, and is about 1/10 of the calcium depletion rate.

Happy Reefing.