Magnesium

[benray4fun]

Is dosing magnesium and/or any other element absolutely necessary for sps?...

I can get everything else to grow, but not my sps..."please shed some light"....THANKS

[Jar*Head]

Can you please post your parameter, Ca, Mg, Kh PO4 NO3

[aquarius77]

Yes, any tank will deplete on magnesium over time unless your using a salt mix that is high in it and do a lot of water changing.

You will also have to keep Alk and calcium balanced, some people choose 2 part dosing, some like Kalkwasser and a calcium reactor. No matter what you do your going to have to test and supplement those three things as needed.

[250G]

I had a buddy test my magnesium last week. I have never tested for it before, have never added magnesium, and have done 2 water changes in the last 2 years. My magnesium was 1180 acording to the test.

Originally posted by aquarius77
Yes, any tank will deplete on magnesium over time unless your using a salt mix that is high in it and do a lot of water changing.

You will also have to keep Alk and calcium balanced, some people choose 2 part dosing, some like Kalkwasser and a calcium reactor. No matter what you do your going to have to test and supplement those three things as needed.

[JB NY]

Originally posted by benray4fun
Is dosing magnesium and/or any other element absolutely necessary for sps?...

I can get everything else to grow, but not my sps..."please shed some light"....THANKS

you should not have to dose magnesium if you are using a ca reactor or some other alk./ca supplementation. If the salt you are using for your tank is not deficient in mag then you should not have to dose at all.

[benray4fun]

Originally posted by JB NY
you should not have to dose magnesium if you are using a ca reactor or some other alk./ca supplementation. If the salt you are using for your tank is not deficient in mag then you should not have to dose at all.

I'm using IO and it's deficient in mag so I have to dose at least a little something. I have to buy a test kit first...

[JB NY]

I used IO for a while. Just put some mag in the newely made salt water before a change and you should be good to go.

[250G]

At what level (ppm) makes a salt mag. deficient?

Originally posted by benray4fun
I'm using IO and it's deficient in mag so I have to dose at least a little something. I have to buy a test kit first...

[ek9vboi]

Originally posted by 250G
At what level (ppm) makes a salt mag. deficient?

I believe its 1250, mine tested 1215 with salifert last night. I've only started to use Reef complete made by Seachem to up my calcium w/ new water being mixed. It also says it brings up magnesium and some other chemical.

[JB NY]

I bump mine up if I measure it anything less than 1300.

[stony_corals]

You may need to dose Mg. If you're using kalk or potentially two part, the pH may be so high locally that Mg will precipitate. That white that you see when dosing kalk is MgOH-, since Mg is not saturated in seawater it should redissolve when the local pH drops......

[JB NY]

How high does the pH need to be?

[stony_corals]

I don't remember exactly, but with sat. kalk, local pH can easily be in the 9s....

[aquarius77]

Originally posted by 250G
I had a buddy test my magnesium last week. I have never tested for it before, have never added magnesium, and have done 2 water changes in the last 2 years. My magnesium was 1180 acording to the test.

Thats pretty low IMO.

[aquarius77]

Originally posted by JB NY
you should not have to dose magnesium if you are using a ca reactor or some other alk./ca supplementation. If the salt you are using for your tank is not deficient in mag then you should not have to dose at all.

So how does the magnesium get replaced from an alk / cal supplement like Kalk? How does a calcium reactor supply mag?

[aquarius77]

Originally posted by stony_corals
I don't remember exactly, but with sat. kalk, local pH can easily be in the 9s....

Saturated limewater will have a pH reading in the 12's.

[JB NY]

Originally posted by aquarius77
So how does the magnesium get replaced from an alk / cal supplement like Kalk? How does a calcium reactor supply mag?

There has to be mag in alk/ca supplements or in ca reator effluent. Because once my tank levels are in line. As long as I make sure that my water change SW is at the correct mag levels. I never ever had to add mag supplemention to my tank. And I had a very high load of SPS corals.

[BLKTANG]

Originally posted by aquarius77
Thats pretty low IMO.

Low or not,have u seen his tank.


Just goes to show,what works for 1 dosent always work for another.

[aquarius77]

How often are you changing water JB? It sounds like you ramp up your mag in the water change so in essence you are dosing mag.

I know there is no mag in Kalk. I do not use a calcium reactor and dont claim to know them inside and out . Altho i can see how it might buffer the water up in terms of alk because it is disolving substrate basically.

[aquarius77]

You are correct blk. i run my mag higer than some but natural seawater has 1300 - 1500 ppm Mag so 1180 is low in the ocean and its low in a tank. i never said it was going to crash his tank, just low.

[JB NY]

Originally posted by aquarius77
How often are you changing water JB? It sounds like you ramp up your mag in the water change so in essence you are dosing mag.

When using IO, wich had mag levels of about 1100. First I got my tank up to 1300 through supplemention using ESV magnesium. Then I just uped my water change SW to 1300 from 1100.

I change out about 13% weekly.

[mile sq. reefer]

JB, like BLKTANG said "Have they seen your tank?" Its truly spectacular. An inspiration to those who wish to take the challenge to sucessfully keep an SPS system. Oh by the way I use RC and my M++ is like 1500. I don't supplement for it at all. I do weekly 5g water changes mixed to 1.025 and top off with Kalk 1tsp per gallon RO/DI water. Calcium 420, PH 8.2 Alk 8-9.

[dandy7200]

Hmmm....I used to test my Mag all the time, then I didn't for about 6 months and just added a little seachem reef complete to my fresh mixed saltwater to bump the Mag and calcium. I did a full round of testing last week when I noticed my coraline shedding a bit from the back glass and found my mag was 930!!!! After a week of dosing Randy's mag solution with Mag flake and Epsom salts I have the level back up to 1400. I run a calcium reactor and drip kalk. My ph is usually on the higher end around 8.5 highs and 8.1 lows. I have been racking my brain for the last week trying to figure out where the mag went, did it precipitate? Did it get used by the coraline? Did the GFO suck it from the water (this has been my thought) ? What do you guys think?

[Billybeau1]

Originally posted by JB NY
you should not have to dose magnesium if you are using a ca reactor or some other alk./ca supplementation. If the salt you are using for your tank is not deficient in mag then you should not have to dose at all.

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.

Calcium reactors have nothing to do with magnesium levels.

NSW is about 1290 ppm . Magnesium plays an important role in the balance of calcium and alkalinity.

benray, please give us all of your parameters and what test kits you use to get these figures. Also what salt mix you use and where do you keep your salinity at and how do you measure.

Then we will know why your sps are not doing well.

[carib]

It takes ca place.