do i need to test magnesium?

douglam · 12/13/2007, 11:46 PM

do i need to test magnesium if im doing weekly water changes?

mg426 · 12/13/2007, 11:51 PM

It is not a bad idea at all.

douglam · 12/13/2007, 11:59 PM

what exactly does magnesium do for a tank?

miwoodar · 12/14/2007, 12:24 AM

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

Section titled: Calcium Carbonate and Magnesium and figures 8-10.

Magnesium blocks the formation of calcium carbonate on your rocks and equipment. Without enough magnesium, you will continuously precipitate calcium carbonate like a runaway freight train causing your calcium and alkalinity to drop.

BangkokMatt · 12/14/2007, 01:50 AM

You definitely need to test. Not as regularly as fo other things as Mg is more stable. I test about once a month

dendro982 · 12/14/2007, 09:04 AM

If you have low pH chronically, just to know what your new saltwater contains, and if you are fighting bryopsis with raised Mg. Not weekly, only when you would like to have this information.

I had to raise Mg and Ca in IO salt, in newly prepared water.

miwoodar · 12/14/2007, 11:21 AM

Quote:

Originally posted by BangkokMatt
You definitely need to test. Not as regularly as fo other things as Mg is more stable. I test about once a month

I agree with that - I don't even own a kit. Every few months I pay the LFS a dollar to do it for me. Afterwards, I go to jdieck's calculator (http://home.comcast.net/~jdieck1/chem_calc3.html) to figure out how I am going to tweak it back to 1300, if I need to. If you're doing weekly changes, you probably won't need to do anything. My last water change was in July though (wouldn't recommend this).

Attreui · 12/14/2007, 12:30 PM

If you dose Kalk definitely keep an eye on it. Unless you are perfect with your water changes it can drop and would need to be dosed.

tmz · 12/14/2007, 12:56 PM

Magnesium,calcium and carbonate. The corals use all three in their skeletal mass.There is a large amount in sea water relative to calcium so it takes longer to deplete but when you need to bring it up you'll be surprised at how much you'll need to put in.Salt mixes contain magnesium. Some are high in magnesium. Regular water changes may offset the need to add magnesium depending on system variables such as coral growth and precipitation.

12/13/2007, 11:46 PM	#1
douglam Registered Member Join Date: Oct 2007 Location: Saint Petersburg, FL Posts: 867	do i need to test magnesium? do i need to test magnesium if im doing weekly water changes?

12/13/2007, 11:51 PM	#2
mg426 Registered Member Join Date: Jan 2006 Location: maryland Posts: 6,923	It is not a bad idea at all. __________________ I found a way to make a small fortune running a reef tank. Start with a large fortune. Unofficial President of the SEACLONE haters club Current Tank Info: 125 mixed reef 110 lbs LR, 1x250watt XM 20K MH 2x175watt XM 20K MH on Magetics 2X96 watt actinic PC, 220 watt VHO actinic, 30 gallon refugium, closed loop system powered by Sequence Dart MSX 200 skimmer 38 gallon sump, Oceansmotions squirt

12/14/2007, 12:24 AM	#4
miwoodar Likey the bikey Join Date: Dec 2004 Location: Colorado Posts: 3,371	http://reefkeeping.com/issues/2006-06/rhf/index.php Section titled: Calcium Carbonate and Magnesium and figures 8-10. Magnesium blocks the formation of calcium carbonate on your rocks and equipment. Without enough magnesium, you will continuously precipitate calcium carbonate like a runaway freight train causing your calcium and alkalinity to drop. __________________ Mike On hiatus. I'm either out riding my bicycle, playing with my family, or throwing ferts in my planted tank. Or working. I hope I'm not doing that though. Current Tank Info: 140 DIY Cube

12/14/2007, 01:50 AM	#5
BangkokMatt Registered Member Join Date: Jan 2006 Location: Krung Thep Posts: 3,100	You definitely need to test. Not as regularly as fo other things as Mg is more stable. I test about once a month __________________ I've spent a lot of money on booze, women and fish. The rest I just squandered. Current Tank Info: 150g sps Reef (now FOWLR after a devastating crash due to chiller) , 2x400w MH (Icecap ballast, Lumenmax 2, Reeflux 12k SE), Deltec AP701, Grotech Tec III, Chiller, 2 x Tunze 6101, 1 x 6205 (+ m/c), bla bla

12/14/2007, 09:04 AM	#6
dendro982 Registered Member Join Date: Mar 2006 Location: Canada Posts: 2,963	If you have low pH chronically, just to know what your new saltwater contains, and if you are fighting bryopsis with raised Mg. Not weekly, only when you would like to have this information. I had to raise Mg and Ca in IO salt, in newly prepared water. __________________ Multiple Tank Syndrome: 15g shallow hi light - Xmas tree rocks, nps, sps, clams 6g shallow dark - sun corals collection 5g - sea apples NC12 - tube anemone 20g L - frogfish 125g - filefishes and lion Current Tank Info: 6 BB tanks: NPS, filter feeders and odd fish. LPS, sps and clams too

12/13/2007, 11:59 PM	#3
douglam Registered Member Join Date: Oct 2007 Location: Saint Petersburg, FL Posts: 867	what exactly does magnesium do for a tank?

12/14/2007, 12:30 PM	#8
Attreui Registered Member Join Date: Nov 2004 Location: Florida Posts: 321	If you dose Kalk definitely keep an eye on it. Unless you are perfect with your water changes it can drop and would need to be dosed.

12/14/2007, 12:56 PM	#9
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	Magnesium,calcium and carbonate. The corals use all three in their skeletal mass.There is a large amount in sea water relative to calcium so it takes longer to deplete but when you need to bring it up you'll be surprised at how much you'll need to put in.Salt mixes contain magnesium. Some are high in magnesium. Regular water changes may offset the need to add magnesium depending on system variables such as coral growth and precipitation. __________________ 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.