Best way to lower magnesium?

[littlesilvermax]

Originally Posted by kwirky

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]

Originally Posted by 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.

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.