Low Mg -- Now what

Whys · 01/31/2009, 01:10 AM

I received some very good advice from Michael that I should start testing my magnesium. I'm running out of things to buy in this hobby (ha ha) so decided to get the tester. Yep! My magnesium is definitely a bit low. Around 1230 ppm.

Aquarium log:
http://spreadsheets.google.com/ccc?k...k-Pl84z9NrIvPg

This is likely the result of both the salt I am using (intended more for a FOWLR) and the fact that I'm running carbon 24/7. I've been buffering the alk, since that is also low because of my salt.

So besides replacing my salt, what should be my course of action? Is there a magnesium buffer and is there anything I should know about using one? I know alk and calcium buffers tend to work against each other. So what's the story on Mg?

dots · 01/31/2009, 02:49 AM

Mg actually helps stabilize the Alk/CA relationship. Most Mg supplements found in the store are mainly salt, and are around 8% Mg. To raise you Mg to a substantually higher level, it will take a fair amount to get it there. After that, a salt with a good Mg level will keep it there with regular WC's.

Be careful though as this addition of Mg will raise your SG slowly. I did this recently, even though I knew better spaced out, and raised my SG way too high. It cost me a lot of money in lost SPS.

My own fault, but the reason I am telling you now......dont be like me.

Refer to this article and the following links to review other important chemistry data.

http://reefkeeping.com/issues/2006-06/rhf/index.php

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

http://archive.reefcentral.com/forum...hreadid=102605

Geodriller · 01/31/2009, 02:49 PM

I have been using Seachem powders for a little over a year now. The advantage calcium also maintains Strontium an Mag. Before I used Kents 2 part, and that was the reason for my falling Mag. I switched to Seachems powders, Raised my Mag with their Mag powder, and have not had to use the Mag since. BTW I test my Mag every month or so becouse I drip kalk and everything checks fine. I also checked my Strontium last week and was good as well. I recommend Seachem powder to anyone, but it is about The most potent additive you can find so be careful. BTW 1230mg does not sound that low. That means there is 410ppm calcium available to the corals as long as your ca is that or higher. There should be a 3:1 ratio MG:ca.

Tylt33 · 01/31/2009, 03:54 PM

Quote:

Originally posted by Whys
I received some very good advice from Michael that I should start testing my magnesium. I'm running out of things to buy in this hobby (ha ha) so decided to get the tester. Yep! My magnesium is definitely a bit low. Around 1230 ppm.

Aquarium log:
http://spreadsheets.google.com/ccc?k...k-Pl84z9NrIvPg

This is likely the result of both the salt I am using (intended more for a FOWLR) and the fact that I'm running carbon 24/7. I've been buffering the alk, since that is also low because of my salt.

So besides replacing my salt, what should be my course of action? Is there a magnesium buffer and is there anything I should know about using one? I know alk and calcium buffers tend to work against each other. So what's the story on Mg?

Kent Tech M comes as a pretty well regarded Mg buffer. That might be the way to go.

will16 · 01/31/2009, 05:00 PM

Quote:

Originally posted by Tylt33
Kent Tech M comes as a pretty well regarded Mg buffer. That might be the way to go.

+1 Tech M works fine. There are others as well. 1230 is not really bad. Ideally it should be in the 1300-1350 range or 3x your calc level.

lewismw · 01/31/2009, 05:06 PM

Tech M also here, I buy it in the gallon jugs and add to it my instant ocean water change. I figure the price is about the same as the premium salt after i buy the additive. And i can get IO from my LFS and save shipping

Whys · 01/31/2009, 08:55 PM

Thanks guys. I'll be sure to pick some up.

Klaus777 · 01/31/2009, 09:01 PM

First things first,
bring up the Mag (kent M is good stuff). Don't dose more than one thing at a time, they only percipitate anyhow (ie, alk, cal and mag at one time). Raise one at a time only. Mag first. Mag is to calcium as alk is to pH. A good Mag level will help hold steady calcium levels. Also a good Mag level helps to keep steady alkalinity and in turn pH.
I think that's right. Chemistry is difficult, that's why I never took it in school.

Whys · 01/31/2009, 09:16 PM

Based on what I've read, that sounds about right. Thanks for the pointers.

Tswifty · 01/31/2009, 10:46 PM

Another vote for Tech M... or you can use Randy's recipe (much cheaper).

I recently switched salts for a boost in mag. I used a 50/50 mix of Coralife and IO and ended posting a mag level of 1440.

01/31/2009, 01:10 AM	#1
Whys Moved On Join Date: Mar 2008 Location: Spokane, WA Posts: 3,263	Low Mg -- Now what I received some very good advice from Michael that I should start testing my magnesium. I'm running out of things to buy in this hobby (ha ha) so decided to get the tester. Yep! My magnesium is definitely a bit low. Around 1230 ppm. Aquarium log: http://spreadsheets.google.com/ccc?k...k-Pl84z9NrIvPg This is likely the result of both the salt I am using (intended more for a FOWLR) and the fact that I'm running carbon 24/7. I've been buffering the alk, since that is also low because of my salt. So besides replacing my salt, what should be my course of action? Is there a magnesium buffer and is there anything I should know about using one? I know alk and calcium buffers tend to work against each other. So what's the story on Mg?

01/31/2009, 02:49 AM	#2
dots Registered Member Join Date: Nov 2004 Location: Sacramento, CA Posts: 6,258	Mg actually helps stabilize the Alk/CA relationship. Most Mg supplements found in the store are mainly salt, and are around 8% Mg. To raise you Mg to a substantually higher level, it will take a fair amount to get it there. After that, a salt with a good Mg level will keep it there with regular WC's. Be careful though as this addition of Mg will raise your SG slowly. I did this recently, even though I knew better spaced out, and raised my SG way too high. It cost me a lot of money in lost SPS. My own fault, but the reason I am telling you now......dont be like me. Refer to this article and the following links to review other important chemistry data. http://reefkeeping.com/issues/2006-06/rhf/index.php http://www.advancedaquarist.com/issues/oct2003/chem.htm http://archive.reefcentral.com/forum...hreadid=102605 __________________ ~Doug

01/31/2009, 10:46 PM	#10
Tswifty Registered Member Join Date: Sep 2007 Location: PA Posts: 14,022	Another vote for Tech M... or you can use Randy's recipe (much cheaper). I recently switched salts for a boost in mag. I used a 50/50 mix of Coralife and IO and ended posting a mag level of 1440. __________________ "Enough light? Heck I could go barebottom and grow SPS in the stand!" - DiscoReefRover

01/31/2009, 02:49 PM	#3
Geodriller Registered Member Join Date: Jan 2009 Location: Pekin, Illinois Posts: 257	I have been using Seachem powders for a little over a year now. The advantage calcium also maintains Strontium an Mag. Before I used Kents 2 part, and that was the reason for my falling Mag. I switched to Seachems powders, Raised my Mag with their Mag powder, and have not had to use the Mag since. BTW I test my Mag every month or so becouse I drip kalk and everything checks fine. I also checked my Strontium last week and was good as well. I recommend Seachem powder to anyone, but it is about The most potent additive you can find so be careful. BTW 1230mg does not sound that low. That means there is 410ppm calcium available to the corals as long as your ca is that or higher. There should be a 3:1 ratio MG:ca.

01/31/2009, 05:06 PM	#6
lewismw Registered Member Join Date: Aug 2004 Location: Birmingham Posts: 275	Tech M also here, I buy it in the gallon jugs and add to it my instant ocean water change. I figure the price is about the same as the premium salt after i buy the additive. And i can get IO from my LFS and save shipping

01/31/2009, 08:55 PM	#7
Whys Moved On Join Date: Mar 2008 Location: Spokane, WA Posts: 3,263	Thanks guys. I'll be sure to pick some up.

01/31/2009, 09:01 PM	#8
Klaus777 Registered Member Join Date: Jul 2008 Location: Kitchener, ontario Posts: 244	First things first, bring up the Mag (kent M is good stuff). Don't dose more than one thing at a time, they only percipitate anyhow (ie, alk, cal and mag at one time). Raise one at a time only. Mag first. Mag is to calcium as alk is to pH. A good Mag level will help hold steady calcium levels. Also a good Mag level helps to keep steady alkalinity and in turn pH. I think that's right. Chemistry is difficult, that's why I never took it in school.

01/31/2009, 09:16 PM	#9
Whys Moved On Join Date: Mar 2008 Location: Spokane, WA Posts: 3,263	Based on what I've read, that sounds about right. Thanks for the pointers.