Magnesium Question

foredababy · 07/30/2016, 09:00 AM

Hello, I was hoping to get some feedback on a magnesium dosing question. I currently just add a few ml each day of Mg concentrate into my sump and I feel I get decent results. Mg right now is 1250, I test weekly with Red Sea magnesium pro test. I dose my calcium and alkalinity via ATO. I was wondering if I could add Mg to the ATO reservoir after I added kalk to it?

foredababy · 07/30/2016, 11:02 AM

I guess my concern is that it will precipitate.

foredababy · 07/30/2016, 06:15 PM

Anybody? Somebody? I guess I can experiment on a small level and see. I'm thinking this is so obvious that everyone is laughing or no one knows. Any feedback is welcome

tmz · 07/31/2016, 10:27 AM

Magnesium will precipitate in limewater. This article has more:

http://www.advancedaquarist.com/2003/12/chemistry

from it :

"...The magnesium in solution was depleted by a factor of more than a hundred compared to what would have been in solution had it all been soluble.... "

"....As anticipated, relative to calcium, magnesium is enriched by a factor of 13 in the sludge compared to the solid quicklime....."

disc1 · 07/31/2016, 10:41 AM

Quote:

Originally Posted by foredababy

Hello, I was hoping to get some feedback on a magnesium dosing question. I currently just add a few ml each day of Mg concentrate into my sump and I feel I get decent results. Mg right now is 1250, I test weekly with Red Sea magnesium pro test. I dose my calcium and alkalinity via ATO. I was wondering if I could add Mg to the ATO reservoir after I added kalk to it?

If you add your magnesium supplement to the kalk in the ATO two things will happen. The magnesium and part of the alkalinity from the kalk will precipitate as either Mg(OH)2 or as MgCO3 depending on how much CO2 gets to the ATO.

And on top of that the sulfate in the mag supplement will precipitate the calcium from the kalk as CaSO4.

foredababy · 07/31/2016, 12:15 PM

Thanks for your time. I will not.

tmz · 08/01/2016, 10:11 AM

You are welcome.

(Kalk wasser) calcium hydroxide/ limewater doesn't deliver much if any soluble magnesium since almost all of the magnesium in the kalk powder or added will precipitate as noted .

Some of the two part commercial mixes provide a small a small amount : calcium reactor dosing adds some as well .

Sometimes, folks seem to require magnesium dosing more when using kalk vs the other methods noted or just assume they need to dose it .

I've been using kalk for calcium and alk suplementation for about 8 years and haven't needed to dose magnesium , in several years. In my aquarium system the food and small water changes keep it in the 1450 range. I test it monthly.So, if you are doing water changes with a salt with a moderate to high magnesium content and feeding well you may not need to dose it ,continuously.

foredababy · 08/01/2016, 11:50 AM

Out of curiosity, what foods raise the magnesium level?

tmz · 08/01/2016, 12:27 PM

No particular type that I know of ; most if not all marine oragisms take up magnesium; so most foods will contribute some . Here's a partial table:

Food Calcium Concentration (ppm) Calcium added to 100 gallon tank in 1 year (ppm in aquarium) Magnesium Concentration (ppm) Magnesium added to 100 gallon tank in 1 year (ppm in aquarium)
Formula One 800 4 280 1
Formula Two 1700 8 290 1
Prime Reef 860 4 290 1
Lancefish 4700 23 520 3
Silversides 4300 21 560 3
Brine Shrimp 140 1 300 1
Plankton 1700 8 520 3
Golden Pearls 8700 42 920 4
Gold Flakes 7200 35 1300 6
Tahitian Blend 440 2 290 1
Saltwater Staple 17000 82 1800 9
Nori 2400 12 2900 14

from this article:

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

foredababy · 08/01/2016, 01:12 PM

Very interesting! I had no idea....thx again

tmz · 08/03/2016, 11:38 AM

You are welcome.

07/30/2016, 09:00 AM	#1
foredababy Registered Member Join Date: Jul 2006 Location: Wichita, Ks Posts: 100	Magnesium Question Hello, I was hoping to get some feedback on a magnesium dosing question. I currently just add a few ml each day of Mg concentrate into my sump and I feel I get decent results. Mg right now is 1250, I test weekly with Red Sea magnesium pro test. I dose my calcium and alkalinity via ATO. I was wondering if I could add Mg to the ATO reservoir after I added kalk to it? __________________ Red Sea Reefer 525xl (109 gal DT), LED's, Waterfall Algae Scrubber, R Octopus skimmer 202 classic, UV Sterilizer, Tunze osmolator, Neptune Apex Controller, Ecotech Vectra M1 return, Jabao PP-20's Current Tank Info: 109 gal mixed reef

07/30/2016, 11:02 AM	#2
foredababy Registered Member Join Date: Jul 2006 Location: Wichita, Ks Posts: 100	I guess my concern is that it will precipitate. __________________ Red Sea Reefer 525xl (109 gal DT), LED's, Waterfall Algae Scrubber, R Octopus skimmer 202 classic, UV Sterilizer, Tunze osmolator, Neptune Apex Controller, Ecotech Vectra M1 return, Jabao PP-20's Current Tank Info: 109 gal mixed reef

07/30/2016, 06:15 PM	#3
foredababy Registered Member Join Date: Jul 2006 Location: Wichita, Ks Posts: 100	Anybody? Somebody? I guess I can experiment on a small level and see. I'm thinking this is so obvious that everyone is laughing or no one knows. Any feedback is welcome __________________ Red Sea Reefer 525xl (109 gal DT), LED's, Waterfall Algae Scrubber, R Octopus skimmer 202 classic, UV Sterilizer, Tunze osmolator, Neptune Apex Controller, Ecotech Vectra M1 return, Jabao PP-20's Current Tank Info: 109 gal mixed reef

07/31/2016, 10:27 AM	#4
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	Magnesium will precipitate in limewater. This article has more: http://www.advancedaquarist.com/2003/12/chemistry from it : "...The magnesium in solution was depleted by a factor of more than a hundred compared to what would have been in solution had it all been soluble.... " "....As anticipated, relative to calcium, magnesium is enriched by a factor of 13 in the sludge compared to the solid quicklime....." __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals. Last edited by tmz; 07/31/2016 at 10:35 AM.

07/31/2016, 12:15 PM	#6
foredababy Registered Member Join Date: Jul 2006 Location: Wichita, Ks Posts: 100	Thanks for your time. I will not. __________________ Red Sea Reefer 525xl (109 gal DT), LED's, Waterfall Algae Scrubber, R Octopus skimmer 202 classic, UV Sterilizer, Tunze osmolator, Neptune Apex Controller, Ecotech Vectra M1 return, Jabao PP-20's Current Tank Info: 109 gal mixed reef

08/01/2016, 10:11 AM	#7
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	You are welcome. (Kalk wasser) calcium hydroxide/ limewater doesn't deliver much if any soluble magnesium since almost all of the magnesium in the kalk powder or added will precipitate as noted . Some of the two part commercial mixes provide a small a small amount : calcium reactor dosing adds some as well . Sometimes, folks seem to require magnesium dosing more when using kalk vs the other methods noted or just assume they need to dose it . I've been using kalk for calcium and alk suplementation for about 8 years and haven't needed to dose magnesium , in several years. In my aquarium system the food and small water changes keep it in the 1450 range. I test it monthly.So, if you are doing water changes with a salt with a moderate to high magnesium content and feeding well you may not need to dose it ,continuously. __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals. Last edited by tmz; 08/01/2016 at 10:17 AM.

08/01/2016, 11:50 AM	#8
foredababy Registered Member Join Date: Jul 2006 Location: Wichita, Ks Posts: 100	Out of curiosity, what foods raise the magnesium level? __________________ Red Sea Reefer 525xl (109 gal DT), LED's, Waterfall Algae Scrubber, R Octopus skimmer 202 classic, UV Sterilizer, Tunze osmolator, Neptune Apex Controller, Ecotech Vectra M1 return, Jabao PP-20's Current Tank Info: 109 gal mixed reef

08/01/2016, 12:27 PM	#9
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	No particular type that I know of ; most if not all marine oragisms take up magnesium; so most foods will contribute some . Here's a partial table: Food Calcium Concentration (ppm) Calcium added to 100 gallon tank in 1 year (ppm in aquarium) Magnesium Concentration (ppm) Magnesium added to 100 gallon tank in 1 year (ppm in aquarium) Formula One 800 4 280 1 Formula Two 1700 8 290 1 Prime Reef 860 4 290 1 Lancefish 4700 23 520 3 Silversides 4300 21 560 3 Brine Shrimp 140 1 300 1 Plankton 1700 8 520 3 Golden Pearls 8700 42 920 4 Gold Flakes 7200 35 1300 6 Tahitian Blend 440 2 290 1 Saltwater Staple 17000 82 1800 9 Nori 2400 12 2900 14 from this article: http://www.advancedaquarist.com/2003/10/chemistry __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.

08/01/2016, 01:12 PM	#10
foredababy Registered Member Join Date: Jul 2006 Location: Wichita, Ks Posts: 100	Very interesting! I had no idea....thx again __________________ Red Sea Reefer 525xl (109 gal DT), LED's, Waterfall Algae Scrubber, R Octopus skimmer 202 classic, UV Sterilizer, Tunze osmolator, Neptune Apex Controller, Ecotech Vectra M1 return, Jabao PP-20's Current Tank Info: 109 gal mixed reef

08/03/2016, 11:38 AM	#11
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	You are welcome. __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.