Magnesium Dosing Question

TRG100 · 02/19/2012, 08:04 PM

Results after my water change:

SG – 1.025
Calcium – 360
Magnesium – 1260
Amm – 0
Nitrites – 10
Nitrates – 0
pH – 8
KH – 12.8
Alk – 4.56

So I dosed with 7.5 ml of Magnesium (30 gallon tank). Performed all the tests again about 4 hrs later. All results were the same but the Magnesium went up to 1290. Not thinking I dosed again with another 7.5 ml trying to get my Magnesium up closer 1380.

Do I keep doing until I get the desired reading or wait? And if I wait how long in-between doses?

jimmy frag · 02/19/2012, 08:12 PM

whats the big deal on keeping it at 1380. is there something depleting it or you just want it higher. i would be more concerned that your alk is high. this is my opinion of cource. what are you keeping and how much .

TRG100 · 02/19/2012, 08:17 PM

Quote:

Originally Posted by jimmy frag

whats the big deal on keeping it at 1380. is there something depleting it or you just want it higher. i would be more concerned that your alk is high. this is my opinion of cource. what are you keeping and how much .

What I've read is Mag. should be about 1380-1400. Figured I'm low I should dose?

When you ask what I am keeping and how much I'm going to assume you mean my corals? Just want to be clear.

My Alk was much higher last water change over 20. I was using buffers for pH and it was driving my Alk way up. Hoping the next water change brings it down lower.

Sugar Magnolia · 02/20/2012, 09:35 AM

Stop dosing for alk and it should come down on it's own. Magnesium should ideally be between 1250-1350ppm. You can bring it up some and it will help you to raise your calcium. http://www.reefkeeping.com/issues/2004-05/rhf/index.php

Hextall · 02/20/2012, 10:43 AM

I'm dosing now for Mg (was around 1100, trying to get up to 1300 or so). From what I've read (and the link above is one of the places I read about dosing), you don't want to raise it too fast... at the most 100 ppm per day.

Apparently, raising Mg too fast can damage creatures. Like many things in this hobby... slower is better.

Did you test after the 2nd dose? Is it a constant ~30ppm per 7.5 ml added? If so, then I think you could increase the volume of the Mg stock per dose. being overly cautious myself, I'd probably wouldn't do more than 10-15 ml per dose... however if 7.5 ml added to 30 gallons bumped it up 30 ppm in a 30 gal tank... that's soem pretty concentrated stuff. slower is always better.

Palting · 02/20/2012, 12:10 PM

Your are actually in an acceptable mag level. Magnesium consumption is fairly low. If you want it higher, I would just keep adding the 7.5 ml daily or every other day, and then repeat the test in a few days. I like to keep mine at about 1350. Although I dose large amounts of calcium and alk due to the stonies in my tank, I find that I only dose mag maybe once every several weeks.

02/19/2012, 08:04 PM	#1
TRG100 Registered Member Join Date: Dec 2011 Location: Somerset Township, NJ Posts: 101	Magnesium Dosing Question Results after my water change: SG – 1.025 Calcium – 360 Magnesium – 1260 Amm – 0 Nitrites – 10 Nitrates – 0 pH – 8 KH – 12.8 Alk – 4.56 So I dosed with 7.5 ml of Magnesium (30 gallon tank). Performed all the tests again about 4 hrs later. All results were the same but the Magnesium went up to 1290. Not thinking I dosed again with another 7.5 ml trying to get my Magnesium up closer 1380. Do I keep doing until I get the desired reading or wait? And if I wait how long in-between doses?

02/20/2012, 09:35 AM	#4
Sugar Magnolia Registered Member Join Date: Feb 2003 Location: Northern VA Posts: 17,691	Stop dosing for alk and it should come down on it's own. Magnesium should ideally be between 1250-1350ppm. You can bring it up some and it will help you to raise your calcium. http://www.reefkeeping.com/issues/2004-05/rhf/index.php __________________ Adrienne The only thing to fear is fear itself....and spiders.

02/20/2012, 10:43 AM	#5
Hextall Registered Member Join Date: Jun 2011 Location: Newmarket, NH Posts: 327	I'm dosing now for Mg (was around 1100, trying to get up to 1300 or so). From what I've read (and the link above is one of the places I read about dosing), you don't want to raise it too fast... at the most 100 ppm per day. Apparently, raising Mg too fast can damage creatures. Like many things in this hobby... slower is better. Did you test after the 2nd dose? Is it a constant ~30ppm per 7.5 ml added? If so, then I think you could increase the volume of the Mg stock per dose. being overly cautious myself, I'd probably wouldn't do more than 10-15 ml per dose... however if 7.5 ml added to 30 gallons bumped it up 30 ppm in a 30 gal tank... that's soem pretty concentrated stuff. slower is always better. __________________ 29g BC Build: http://reefcentral.com/forums/showthread.php?t=2061189

02/20/2012, 12:10 PM	#6
Palting Registered Member Join Date: Apr 2010 Location: Ohio Posts: 6,912	Your are actually in an acceptable mag level. Magnesium consumption is fairly low. If you want it higher, I would just keep adding the 7.5 ml daily or every other day, and then repeat the test in a few days. I like to keep mine at about 1350. Although I dose large amounts of calcium and alk due to the stonies in my tank, I find that I only dose mag maybe once every several weeks. __________________ Anything I post is just an opinion. One of many in this hobby. Believe and follow at your own risk of rapid and complete annihilation of all life in your tank :) Current Tank Info: Incept 3/2010, 150 RR, 50g sump, 20g fuge, 150w 15K MH x3, T5 actinics x8, moonlight LED x6, 1400gph return, Koralia 1400 x4, 300 g skimmer, 4 tangs, 2 mandarins, 2 perc, 6 line, 3 cardinals, 2 firefish, SPS, LPS, zoas, palys, shrooms, clam

02/19/2012, 08:12 PM	#2
jimmy frag Registered Member Join Date: Oct 2010 Location: burlington ontario Posts: 845	whats the big deal on keeping it at 1380. is there something depleting it or you just want it higher. i would be more concerned that your alk is high. this is my opinion of cource. what are you keeping and how much .