Best way to lower magnesium?

[Jaws]

I was wondering if there is a better or easier way to lower magnesium other than doing a water change?

[Veng68]

I don't see any other option besides water change.

Cheers,
Aquaman

[StirCrazy]

I was wondering if there is a better or easier way to lower magnesium other than doing a water change?

how high is it? and how did it get that high?

Steve

[Farrmanchu]

I've heard that kalk dosing precipitates Mg, a bit at a time.

[Beverly]

Because of a faulty Salifert Mg test kit, I kept adding Mg over a period of a couple of months. With a new test kit, I realized I had Mg higher than 1500 ppm. It didn't do any harm. I just did regular weekly 15% water changes and let the tank slurp up the extra Mg.

[Jaws]

My Mg was up to about 1325 then I did a 40% water change last night. I dosed appropriately but somehow the Mg ended up being about 1470. I'm just worried because it was such a big jump and some of my corals seemed to have the tips burned off and even parts of their sides after I started dosing Mg a month or so ago.

[Beverly]

Jason,

How big is your tank? Did you add the Mg all at once (like dump it into the tank or sump), or did you add it bit by bit in a high flow area in the tank, or what?

I don't have a sump to add my additives to, so I calculate how much additive I need with the The Reef Chemistry Calculator (http://home.comcast.net/~jdieck1/chem_calc3.html), and add it 10 mls at a time with a baby medicine syringe into high flow areas in my 120g. Have never had any coral burning from adding buffer, Ca or Mg with this method.

[littlesilvermax]

Holy crap!

In all honestly once the corals adapt 1500 shouldn't be too high, but I would try and keep it under 1400. Also too much magnesium at once could introduce a bit of ammonia. I have never measured any, but if you raised your tank by 200 ppm all at once that could end up with big problems. Of course if the damage is already done then do water changes.

Many recommend only raising magnesium by a max of 50 ppm per day. I would suggest 50 ppm per week, to be on the safe side.

Did you try my method of only dosing your newly made up salt water?

Once you get that method figured out it works really really well. Best of all you never dose the tank only newly made up water.

Look at post #2. (http://www.canreef.com/vbulletin/showthread.php?t=26590)

[Jaws]

Did you try my method of only dosing your newly made up salt water?

Ya, that's the method I used. My tank is 180G with about 40G in the sump. My Mg was at 1325, which I reached gradually through adding Mg dissolved in top off water and in biweekly water changes. I was doing an 80G water change this time so I mixed the Mg in the fresh water before adding salt until it dissolved. I added the salt, tested and Mg was about 1400. I added the new water to the tank and tested about an hour after and the Mg read 1470. I tested agian tonight and here's what I got:

Mg 1425
Alk 11.5
Ca 420
NO3 0.5
PO4 0

Do you think I still need to do a water change or should I be ok?

[Farrmanchu]

IMO, you should be fine, I just can't figure out where the jump came from.

[StirCrazy]

My Mg was up to about 1325 then I did a 40% water change last night. I dosed appropriately but somehow the Mg ended up being about 1470. I'm just worried because it was such a big jump and some of my corals seemed to have the tips burned off and even parts of their sides after I started dosing Mg a month or so ago.

don't worry about that, changing in now a few days later will be more of a strain on stuff as you are putting them through the change twice. and 1375 to 1470 isn't really a big jump for Mg.. I have done 400ppm jumps with no adverse effects.

the dosing how are you doing it though and why are you doing a regular dosing routine for Mg? I just check mine after every water change and adjust at that point as I find it stays constant after it is fixed.

Steve

[littlesilvermax]

Ya, that's the method I used. My tank is 180G with about 40G in the sump. My Mg was at 1325, which I reached gradually through adding Mg dissolved in top off water and in biweekly water changes. I was doing an 80G water change this time so I mixed the Mg in the fresh water before adding salt until it dissolved. I added the salt, tested and Mg was about 1400. I added the new water to the tank and tested about an hour after and the Mg read 1470. I tested agian tonight and here's what I got:

Mg 1425
Alk 11.5
Ca 420
NO3 0.5
PO4 0

Do you think I still need to do a water change or should I be ok?


What salt are you using? IO naturally (at least the 10 or so that I have tested) runs about 1200 so I bump it up to 1380.

Are your corals doing OK now?

[kwirky]

What salt are you using? IO naturally (at least the 10 or so that I have tested) runs about 1200 so I bump it up to 1380.

Are your corals doing OK now?

yeah i use OceanPure, and I gotta be careful, because when I set up my system initially, the Mg was at a skyhigh 1550 or so. Somebody else who uses the same salt gets about 1350 from it, so I think it was the batch.

could be a batch that you got? Did you test it before dosing? I learned from my own experience there that I should test the newly mixed saltwater before I put it in, so I know what to dose safely.

I bought a big thing of magnesium dosing stuff, and I haven't even cracked it open yet because of where the Mg's at.

[littlesilvermax]

yeah i use OceanPure, and I gotta be careful, because when I set up my system initially, the Mg was at a skyhigh 1550 or so. Somebody else who uses the same salt gets about 1350 from it, so I think it was the batch.

could be a batch that you got? Did you test it before dosing? I learned from my own experience there that I should test the newly mixed saltwater before I put it in, so I know what to dose safely.

I bought a big thing of magnesium dosing stuff, and I haven't even cracked it open yet because of where the Mg's at.

Good point! I always test my IO when I get a new batch, to ensure my mixing recipe stays the same.

Also, remember that magnesium (as is alk & calcium) go up proportionally to SG.

[littlesilvermax]

Another thing I though of today regarding magnesium:

I don;t know the chemical reason why, but I have heard before that when you test your water you should wait a day or two for your parameter to settle. Almost like they will not read accurately on a test kit right away. If you are adding something (magnesium, alk, calcium) then you should add some, then test a couple days later and add more.

Perhaps your tank was running higher then your test kits showed, and after a few days they would have showed it. Magnesium will not suddenly increase on its own.

[Jaws]

Hey guys. Sorry it's taken so long for me to write back. Thanks for your replys. Littlesilvermax: I think you're right. I tested the main tank water about a half hour after adding the water change water. I was in a bit of a hurry to do the water change too so I only waited about an hour for the Mg to dissolve in the new water and then about three hours for the salt to dissolve so that probably didn't help. The corals are all looking fine. I'm starting to wonder if the dying tips were a result of too much ozone. I discontinued the use of ozone and I haven't noticed any more tissue loss.
Steve: I don't dose Mg regularily but I did add it a little bit at a time with my top off water for the first few weeks to get up past the 1300 mark. Now I should be able to maintain it with water changes plus Mg.

I tested the water change water after the salt dissolved before adding the Mg and it tested at 1180. I use Kent salt. Sometimes you never know how accurate you're being with those test kits though. Some of the salifert test kits ask you to add a scoop of whatever powder you're using but some specify to use a level scoop and some don't specify at all. I've just been using a level scoop on all of them and hoping that's what they want. Everything still looks good though so I don't think I have anything to worry about at this point.

Littlesilvermax: You mentioned in your vendor posts that you use Randy's recipe. Before I added Mg to the water change water I looked at this chemistry calculator to see what it recommends dosing:

http://jdieck1.home.comcast.net/chemcalc.html

I referenced the Mag Flake recipe and Randy's recipe to see what it recommended. They were both quite far apart but the Randy's recipe was pretty high. Do you use his recipe exactly or a variation of it?

Thanks again for all your help guys.

[littlesilvermax]

Hey guys. Sorry it's taken so long for me to write back. Thanks for your replys. Littlesilvermax: I think you're right. I tested the main tank water about a half hour after adding the water change water. I was in a bit of a hurry to do the water change too so I only waited about an hour for the Mg to dissolve in the new water and then about three hours for the salt to dissolve so that probably didn't help. The corals are all looking fine. I'm starting to wonder if the dying tips were a result of too much ozone. I discontinued the use of ozone and I haven't noticed any more tissue loss.
Steve: I don't dose Mg regularily but I did add it a little bit at a time with my top off water for the first few weeks to get up past the 1300 mark. Now I should be able to maintain it with water changes plus Mg.

I tested the water change water after the salt dissolved before adding the Mg and it tested at 1180. I use Kent salt. Sometimes you never know how accurate you're being with those test kits though. Some of the salifert test kits ask you to add a scoop of whatever powder you're using but some specify to use a level scoop and some don't specify at all. I've just been using a level scoop on all of them and hoping that's what they want. Everything still looks good though so I don't think I have anything to worry about at this point.

Littlesilvermax: You mentioned in your vendor posts that you use Randy's recipe. Before I added Mg to the water change water I looked at this chemistry calculator to see what it recommends dosing:

http://jdieck1.home.comcast.net/chemcalc.html

I referenced the Mag Flake recipe and Randy's recipe to see what it recommended. They were both quite far apart but the Randy's recipe was pretty high. Do you use his recipe exactly or a variation of it?

Thanks again for all your help guys.

The recipe I use is Randy's recipe, but I don't dissolve in water and then add to the tank, I dose differently. Randy's recipe has changed a bit though over the years.

Mixing in the magnesium and then 1 hour later mixing the salt should be fine, I do it sometimes.

I think it is when you test the water that you have to wait a while before testing or else tests are off.

I wouldn't worry about one level scoop, overflowing scoop, etc. That scoop is to precipitate calcium (really, 1/2 scoop is likely good enough, but a little more or less doesn't really matter) and then the titration measures magnesium. If you didn't add the scoop of powder in your test kit you would be measuring total calcium and magnesium combined.

Glad everything looks good.

Remember, patient. Good things happen slowly, bad things happen fast. If your magnesium is low, bring it up slowly a little at a time. I would prefer going from say 1000ppm to 1380ppm to take 3 months rather then 1 week.