How fast can I raise my magnesium level?

Bustyraker · May 10, 2017

I've been pretty lazy with testing lately and I almost never test for mag anyway. Needless to say I had an alk spike and ended up testing everything when I got home today. My mag dropped to 1170 and I want to get it up to 1300 or so. It will take around 1000ml of solution to get it there. How much can I dose in a day?

Mal11224 · May 10, 2017

Hi. It is about 1ml/gal per day. That is the max. I would do 10ml per hour until you reach the max. Test daily to see what the level is.

120reefkeeper · May 10, 2017

No more than 100ppm per 24 hours.

AmericanAquariums · May 10, 2017

I can tell you from experience I have raised my mag hundreds of ppm in a single day with no negative effects. I have done this many many times.

120reefkeeper · May 10, 2017

This is the calculator I use and it gives you warnings on how much to dose.

http://reef.diesyst.com/chemcalc/chemcalc.html

Mr.Brightside · May 10, 2017

Magnesium is hard to overdose but 10PPM is the MAX per day if we're going by the book. For Calcium it would be 20PPM and Alkalinity it would be 1.4dKH or 0.5 meq/L.

Randy Holmes-Farley · May 11, 2017

The concern with raising magnesium fast is not the magnesium itself, but rather potential impurities in it (ammonia, other metals, etc.).

Trevor40 · Mar 31, 2018

Randy Holmes-Farley said:
The concern with raising magnesium fast is not the magnesium itself, but rather potential impurities in it (ammonia, other metals, etc.).

Great to know, thanks

Denise&JoelRod · Feb 14, 2020

120reefkeeper said:
This is the calculator I use and it gives you warnings on how much to dose.

http://reef.diesyst.com/chemcalc/chemcalc.html

This is a nice calculator. It's one I always use. it is better then the from BRS.

Saltyanimals · Mar 20, 2020

Raised mine 200ppm in one dose before. This was accidental as I was targeting 100pm per day x 2 days as recommended by AF. But somehow the calculator was off and I didn't need the 2nd dose. It went up 200ppm with the single dose. This was with AF Mag so hopefully it's a "cleaner" product and thus the lower impurities that Randy mentioned was the concern.

I think the smaller recommendation is just precautionary. Case in point, imagine that I went with the calculator and dumped the whole thing in.. I would have raised my Mg 400ppm in one sitting.

LOVEROCK · Dec 14, 2020

Randy Holmes-Farley said:
The concern with raising magnesium fast is not the magnesium itself, but rather potential impurities in it (ammonia, other metals, etc.).

You are the man

Noodles_Jefferson · Dec 31, 2021

120reefkeeper said:
This is the calculator I use and it gives you warnings on how much to dose.

http://reef.diesyst.com/chemcalc/chemcalc.html

thank you so much for this! I've been using the BRS calculator but it doesn't provide enough options for different products. it's either BRS liquid or dry chloride or sulfate and a couple of others. This lists red sea mag and gave me a much more accurate dosage.