Magnesium

[JB NY]

Originally posted by Billybeau1
The only salt mixes (that I know of) , that aren't deficient in mag, is Coralife and Oceanic. Please enlighten me if you know of another.

But you should not be dosing in the main tank to raise the levels of anything in a deficient salt mix. What you should do is test the levels of a new bucket of salt you are going to use for water changes. Then add ca or mag or alk or whatever to raise them to the proper levels before your water change. Then for the rest of the bucket always raise the levels before adding it to your tank. When you get a new bucket do the same thing.

[Billybeau1]

I disagree.

Water chemistry is about volume and consumption. You can't match your water change water with your tanks parameters. It just won't work unless you are doing water changes every day.

Not so much Mag, but Cal and Alk are used up in medium to heavily stocked tanks quite rapidly.

If you change 20% of your water with the same parameters as the tanks, in a few days your numbers will fall.

Thats why most folks dose a 2-part every couple of days or even daily.

And you can easily dose calcium and alkalinity in the main tank in a high flow area without problems.

[250G]

Back to the original questoin (the first post), IMO you do not have to supplement anything to your tank is you are using a calcium reactor, including magnessium.

If my magnessium is low and this is bad for my corals, well someone should explain this to my corals because right now my tank has never looked better (and many of you got to see pictures of what it looked like last month). That being said, maybe my mg is low, but I have seen tanks with excellent levels of mg that well, did not look like they were doing too great.

Also, is it just me or is the post I quoted below confusing? I did read the posts...keep it simple people.

Originally posted by Billybeau1
I disagree.

Water chemistry is about volume and consumption. You can't match your water change water with your tanks parameters. It just won't work unless you are doing water changes every day.

Not so much Mag, but Cal and Alk are used up in medium to heavily stocked tanks quite rapidly.

If you change 20% of your water with the same parameters as the tanks, in a few days your numbers will fall.

Thats why most folks dose a 2-part every couple of days or even daily.

And you can easily dose calcium and alkalinity in the main tank in a high flow area without problems.

[capn_hylinur]

Magnesium allows calcium to be suspended in solution in high levels. Without it the calcium would precipitate out in the form of a white powder--being absolutely useless to the corals.
This is why it is important to measure both calcium and magnesium levels.
A desired level is about 1300 but if you go higher there is no documented evidence that it can do harm.

[Billybeau1]

Originally posted by 250G
Back to the original questoin (the first post), IMO you do not have to supplement anything to your tank is you are using a calcium reactor, including magnessium.

If my magnessium is low and this is bad for my corals, well someone should explain this to my corals because right now my tank has never looked better (and many of you got to see pictures of what it looked like last month). That being said, maybe my mg is low, but I have seen tanks with excellent levels of mg that well, did not look like they were doing too great.

Also, is it just me or is the post I quoted below confusing? I did read the posts...keep it simple people.

I don't know.... I re-read it and it makes perfect sense to me. Maybe I just wrote it funny.

250g, what salt mix do you use and do you know what your Mg level is in your tank ?

[JB NY]

Originally posted by Billybeau1
I disagree.

Water chemistry is about volume and consumption. You can't match your water change water with your tanks parameters. It just won't work unless you are doing water changes every day.

I don't agree with that.

You should be able to match most if not all of your levels with your water change Or at least the one I want to.

I use a CA reactor. My ca/alk never fluctuate much at all, it was almost always 8 dKH and 500 Ca, my mag was 1400.

I think the whole point of using a reactor is to minimize ca/alk fluctuations as well as free you up from daily dosing.

So then I would use a salt mix low in alk, and add ca and mag to the water change water if needed.

I don't understand why you say I can't do that, I did just that for years with no problems at all.

[250G]

My mg is 1180 so I was advised by the guy who tested it for me (we had a few pints and from what I recall it is a somewhat complex test). I have done 2 - 40G water changes in the last 2 years and have never supplemented mg and I am all SPS essentially. Must mean my ca reactor is doing something, or not.

Originally posted by Billybeau1
I don't know.... I re-read it and it makes perfect sense to me. Maybe I just wrote it funny.

250g, what salt mix do you use and do you know what your Mg level is in your tank ?

Below is the comment I found confusing. What does this mean?

Originally posted by Billybeau1
If you change 20% of your water with the same parameters as the tanks, in a few days your numbers will fall.

[Billybeau1]

What it means is, in medium to heavily stocked tanks, calcium and alkalinity are consumed quite rapidly. So if one changes water once every two weeks with the same parameters, by the end of the first week, cal and alk will probably be lower than normal.

Now this is where the confusion is coming from.

Calcium reactors are a whole nother ballgame. I don't doubt you CR users are not having any problems keeping cal and alk in check. That's what they do. (I do question the mag though) , but if your tank looks amazing with a mag level of 1180 ppm then I guess you are good to go. BTW - What mag test ?

[JB NY]

Originally posted by 250G
My mg is 1180 so I was advised by the guy who tested it for me (we had a few pints and from what I recall it is a somewhat complex test). I have done 2 - 40G water changes in the last 2 years and have never supplemented mg and I am all SPS essentially.

1150 is about what most salts measure out for magnesium. So depending on the salt you used, it probably won't bring up your mag levels.

[Billybeau1]

Well JB, I don't agree with that, I'm sorry.

IO - 1030 ppm
RC - 1290 ppm
Coralife - 1380 ppm
Oceanic - 1650 ppm

By the way, what does the amount of magnesium in the salt have to do with a calcium reactor ?

I don't think a calcium reactor produces magnesium.

[JB NY]

I thought we were talking about dosing magnesium.

I'm just stating that you should not need to dose magnesium unless something is out of wack. I don't know why we are talking about calcium reactors.

All I am saying is that when I bumped the magnesium in my water for my water change to my tank levels. I never had to dose magnesium it was always at 1400. This was when I used IO, RC, Oceanic, Ocean pure and Tropic Marin. With the exception of Oceanic, I never fouind any of the other slats anywhere near to 1300. Are those the levels that you tested in those salts?

[250G]

I think the person who started this thread is now going to have a complex about magnessium in their reef when it is really not something they should really be that concerned about!

But that's just me. I don't dose it and I don't measure for it. It works for me. As I said someone tested it for me last week and I learned week my mg was 1180. I have no intention of supplementing it as my tank has never looked better. I think the constant desire/search for perfect water can mess up a perfectly good tank, actually I know it can, I see others do it all the time...

[capn_hylinur]

Originally posted by 250G
My mg is 1180 so I was advised by the guy who tested it for me (we had a few pints and from what I recall it is a somewhat complex test). I have done 2 - 40G water changes in the last 2 years and have never supplemented mg and I am all SPS essentially. Must mean my ca reactor is doing something, or not.



Below is the comment I found confusing. What does this mean?

Hi Dave;
Aren't we all losing sight of the fact that magnesium has no direct affect on the coral. Its indirect use is to allow higher levels of calcium to stay dissolved in solution?
I've had my calcium levels at 500 and magnesium at 650(before I smarted up and measured it) and everything was fine(no precipitation)
The corals could care less if it was 650 or 1300 because it is an abiotic factor
Scott

[Serioussnaps]

Originally posted by JB NY
I don't agree with that.

You should be able to match most if not all of your levels with your water change Or at least the one I want to.

I use a CA reactor. My ca/alk never fluctuate much at all, it was almost always 8 dKH and 500 Ca, my mag was 1400.

I think the whole point of using a reactor is to minimize ca/alk fluctuations as well as free you up from daily dosing.

So then I would use a salt mix low in alk, and add ca and mag to the water change water if needed.

I don't understand why you say I can't do that, I did just that for years with no problems at all.

I agree with JB. I can match my tank and compensate for certain paramaters just as he says...its not rocket science.

[aquarius77]

I was told yesterday that a ca reactor DOES put mag back into the tank. "You are dissolving crushed coral" and the way he sees it is the coral has all those elements in it from when it was alive. This is a very interesting topic and i would love to find a definitive answer.

[JB NY]

Originally posted by aquarius77
I was told yesterday that a ca reactor DOES put mag back into the tank.

That's what I always thought as well.

[Greg Hiller]

>IMO you do not have to supplement anything to your tank is you are using a calcium reactor, including magnessium.<

FWIW, that's not been my experience. I use IO, but I boost up the magnesium before doing water changes. Still, over time I find that magnesium levels drop, even when my reactor keeps alkalinity and calcium levels up. FWIW, also find I have to bump calcium up once in a while. I think that many corals take up calcium and magnesium in different ratios. Unless the calcium reactor substrate you are using has the same ratios of calcium to magnesium, you are going to end up with an imbalance over time that you need to correct. At the kind of volumes of water changes that Joe is talking about though I can see how it'd take a lot longer to sneak up on you. 15% per month would be hard for me to keep up with.

[Billybeau1]

I give up on this one.

[Hendersonracing]

you have to add mag with a reactor...I have a mrc2 and dose mag..

[JB NY]

Greg, you need to do more water changes.

I wonder if your Ca reactor is just not keeping up with you tank? If you need to dose Ca once in a while, it would be safe to assume that the reactor is tuned just a little behind the tanks need, it just doesn't show up until a while has past.

Regardless. I don't think that there is a panacea for not having to dose anything ever. I kept crazy good track of everything and every few months I would find that something always needs to be tweaked just a little.

[mmotown]

Originally posted by Hendersonracing
you have to add mag with a reactor...I have a mrc2 and dose mag..

I have a MRC2 as well but I have ARM media in mine. Are you saying there's a media for Mg I can put in there?

[Kiel'thalin]

IME, my magnesium will fall if nothing is dosed. Let me explain...when I 1st bought my Salifert Mag Test Kit, I was in the 900's. Since last December (when I bought the kit) I have dosed 48 ounces of Kent's Liquid Magnesium to maintain the mag levels in my 46g tank. I was using IO salt, but the last 2 water changes have been with RC. I am in the process of dosing a 600mL dose of a randy mag solution for the 1st time because I am sitting at 1200ppm. I don't really see any problems trying to keep your mag at NSW ~1300ppm. I have been using randy's two part for the last 6 months. Here is my testing results:
http://home.mchsi.com/~liztara/Water_Parameter.xls

[JB NY]

FWIW, I used to add 450ml of ESV liquid magnesum to 35gal of freshly made IO before I did a water change. This was done weekly to raise the IO mag levels. You need a lot of magnesium to raise your levels.

[jay24k]

I've never heard of magnesium being calcium reactors. There is some media that some use. If I recall, I think it dolomite or something like that. I go through a ton of media and I still have to dose occasionally. Magnesium is not something you should go through that quick though.

[250G]

Once SPS tanks become very mature, even small size tanks (150G), it can be almost impossible to keep up with calcium demands. A buddy of mine had a very mature 150 and he used 2 calcium reactors (equivalent of a MTC pro-cal) and ran them full blast, you could see the media disolve on a daily basis. He also dosed all his top-up water with kalc. Keeping the calcium above 400 was next to impossible b/c of the size of the SPS colonies. Kid had some masive capricornis colonies.

Originally posted by JB NY
Greg, you need to do more water changes.

I wonder if your Ca reactor is just not keeping up with you tank? If you need to dose Ca once in a while, it would be safe to assume that the reactor is tuned just a little behind the tanks need, it just doesn't show up until a while has past.

Regardless. I don't think that there is a panacea for not having to dose anything ever. I kept crazy good track of everything and every few months I would find that something always needs to be tweaked just a little.