how often do you guys test for Mg?

[glennr1978]

Since I've been getting more, and more interested in sps I've been paying much closer attention to relevant water parameters. I bought an Mg test kit (elos) about a week and a half ago and when I first tested Mg was 1050. I've been dosing Tech M as directed on the bottle since and today Mg is at 1200. Once I get it up to the 1300 - 1400 range how often should I test after that?

 

Right now I test Alk daily, and Ca every 4 or 5 days. For the last month or so both have been pretty stable at 8-9 dkh, and 440.

[geekreef_05]

I never test... and Im an SPS keeper too.

 

I heard some interesting stuff about Alk and Mg this morning, leading to the possibilty that Mg and Alk and linked in some way. Id be interested to see what your results are like after a water change or two.

[glennr1978]

I never test... and Im an SPS keeper too.

 

I heard some interesting stuff about Alk and Mg this morning, leading to the possibilty that Mg and Alk and linked in some way. Id be interested to see what your results are like after a water change or two.

yeah they are linked from what I understand. if Mg is up to par then Alk fluctuates less, and in turn so does Ca. I tested a freshly mixed batch of water about a week ago (seachem reef salt), Mg =1200. So I don't think wc's are going to help me much.

[psam]

I test after big water change and adjust accordingly, or since I often just change a gallon every 5 or so days, I'll test every 2 weeks or so. Doesn't drift down too much, so usually needs no more than 75-100ppm adjustment.

[Izzue]

Yes... CA Mag and Alk...all work together in the correct levels.

 

I get my 2 Part from this sponsor. Im currently using a Seachem Mag kit now

but Im gonna get this one when I need it.

http://www.bulkreefsupply.com/Test-Kits/c6...oduct_info.html

 

0.02

 

Izzue

[cmador]

^^^ I also get my two part from bulkreefsupply.com. I test for Mg once a month with a salifert test kit.

[SeeDemTails]

I dont even dose MG although I have it, and with just dosing ESV I cant even get it below 1500ppm with a salifert test. It is up around 1650ppm. No ill effects on the coral, thats just where it stays.

 

And my bryopsis is still alive.

[cmador]

Another quick point, the rule of thumb for Mg levels is 3X your Ca level. Example - Your Ca is reading 410 so your Mg should be around 1230 (3x410).

[disaster999]

how did you get your elos kit to read 1050ppm? mine only does 100ppm increments

[Alexraptor]

Another quick point, the rule of thumb for Mg levels is 3X your Ca level. Example - Your Ca is reading 410 so your Mg should be around 1230 (3x410).

 

Is that a certainty? Like can one in that case ditch either the calcium test or the magnesium test kits and just calculate both with just the one?

[glennr1978]

how did you get your elos kit to read 1050ppm? mine only does 100ppm increments

Check with elos, your kit may actually read in 75ppm increments (like mine does). They put a sticker on the little card insert over the part that read 1 drop = 100ppm. The sticker says 1 drop =75ppm.

 

Is that a certainty? Like can one in that case ditch either the calcium test or the magnesium test kits and just calculate both with just the one?

apparently not, since in my case I have readings ranging from 1050ppm to 1200ppm for Mg. all the while ca is steady at 440ppm. I think what they were trying to say is that you want to shoot for 3x you Ca levels.

[kinetic]

I test Mg only when I feel like my ALK and Ca is dropping abnormally. It seems to be pretty stable with weekly water changes.

[PurpleUP]

Check with elos, your kit may actually read in 75ppm increments (like mine does). They put a sticker on the little card insert over the part that read 1 drop = 100ppm. The sticker says 1 drop =75ppm.

 

 

apparently not, since in my case I have readings ranging from 1050ppm to 1200ppm for Mg. all the while ca is steady at 440ppm. I think what they were trying to say is that you want to shoot for 3x you Ca levels.

 

Glen, thats ODD. I've been wondering why your tests have been coming out so much differently than mine. Why would they post a sticker on the card insert that reads "1 drop = 75ppm" while mine reads 1dr = 100ppm? Does yours require 9 drops of reagent A and .15 of powdered reagent B? I thought we had the same kits, no? Did you by the "Aqua Test Expert Line" kit? However, if this is the case, then your readings would technically come out lower than mine due to you having to add more drops. Out of curiousity, what is the expiration date on your box? Mine is 09/08.

 

Glen, thats ODD. I've been wondering why your tests have been coming out so much differently than mine. Why would they post a sticker on the card insert that reads "1 drop = 75ppm" while mine reads 1dr = 100ppm? Does yours require 9 drops of reagent A and .15 of powdered reagent B? I thought we had the same kits, no? Did you by the "Aqua Test Expert Line" kit? However, if this is the case, then your readings would technically come out lower than mine due to you having to add more drops. Out of curiousity, what is the expiration date on your box? Mine is 09/08.

 

Weird. I just opened ANOTHER box I had ordered of the same kit, with an expiration of 12/2009 and it *does* have that sticker you're referring to. I'll have to test a new batch of salt tomorrow using BOTH kits. I'll let you know if they come out differently.

[glennr1978]

Glen, thats ODD. I've been wondering why your tests have been coming out so much differently than mine. Why would they post a sticker on the card insert that reads "1 drop = 75ppm" while mine reads 1dr = 100ppm? Does yours require 9 drops of reagent A and .15 of powdered reagent B? I thought we had the same kits, no? Did you by the "Aqua Test Expert Line" kit? However, if this is the case, then your readings would technically come out lower than mine due to you having to add more drops. Out of curiousity, what is the expiration date on your box? Mine is 09/08.

 

 

 

Weird. I just opened ANOTHER box I had ordered of the same kit, with an expiration of 12/2009 and it *does* have that sticker you're referring to. I'll have to test a new batch of salt tomorrow using BOTH kits. I'll let you know if they come out differently.

 

I'm not sure when my kit expires, does it say on the box or something? Nevermind, I just found it. Mine expires 12/09 too.

[dweakl01]

About every 2 -3 months, but I do boost my IO water change with magnesium in between Mg tests.

[bdare]

I'm still testing for Mg once a week. I have some of the Reef Crystals which is low in Mg so I've been testing more often to make sure I keep it up.

 

Mg should be maintained because it helps with the solubility of Ca and Alk. It allows us to keep our parameters higher than NSW without precipitation. There are some great articles on this over at RC in the Chemistry Forum.

 

Ben