How do I lower my Mg levels

[RPatsula]

Hi, I kind of screwed up my magnesium levels in my aquarium by dosing too much magnesium using my BRS 2 par solution. My magnesium level was approximately 1040 and I was raising it 100 ppm per day and inadvertently raised it to 1580 ppm. It has been at that level for approximately one week and I can't seem to get it to go down. My Ca is 400 ppm, Alk is 7, salinity is 1.023. I am doing a 45 gallon water change every second week. My total tank/sump water volume is approximately 280 gallons. I am thinking of changing my water change scheduled to every week until I get the magnesium levels to 1400 ppm.

So is the easiest way to reduce the magnesium levels, is to increase the water change frequency? I have stopped dosing in the meantime.
The direct result of the high magnesium levels so far is my torch coral has completely retracted, I think I may have killed him. Also my green bubble tip anemone has completely retracted as well and is hidden somewhere in my live rock.

Thank you
Rick

[michika]

I've never had adverse impacts from magneisum in my system and I keep my levels as high as yours is now. Remember people with briopsis doing magneisum treatments keep their levels higher then what you've stated with you adverse effects.

Anyways to answer your question you have two options; wait it out or water changes. Essentially you are waiting for you system to use up the available Mg. A word of caution with the water change method though, if your salt is high in Mg you're not going to be getting the results you hoped for.

Sounds like your torch and bubble coral are just miffed and laying off the dosing for a few days will probably bring them right back out. Additionally my question to you would be how are you sure that the retraction of two LPS corals are a direct link to high Mg? I'm just playing the devil's advocate here.

Good luck.

[Magickiwi]

What's your calcium level? I read an article a few days ago about magnesium control being complicated due to Mg+Ca precipitation. I'm sure there are people with more knowledge on this but if you dose Ca and it causes extra Mg to form a precipitate then you've effectively lowered your Mg levels.

But unless your Ca is low I'd wait for an expert on this reaction before trying it. I could be leading you down the path :S

[RPatsula]

here are some of my readings from the past 2 months. my salinity has been consistantly between 1.023 and 1.026

9-19-2013
mg 1040
ca 310
kh 7.0
pH 8.37


10-21-2013
mg 1080
ca 340
kh 5.9
pH 8.33


10-25-2013
mg 1240
ca 325
kh 6.3
pH 8.37

10-29-2013
mg 1480
ca 330
kn 5.8
pH 8.41

10-31-2013
mg 1530
ca 345
kh 6.3
pH 8.39

11-1-2013
mg 1380
ca 350
kh 6.4
pH 8.36

11-4-2013
mg 1520
ca 400
kh 6.4
pH 8.43

11-5-2013
mg 1540
ca 350
kh 6.5
pH 8.42

[Magickiwi]

Feedback: Your Ca and dKH values are a little low for http://www.reefkeeping.com/issues/2004-05/rhf/index.php and if you agree with other members your pH isn't worth tracking.

At this point I'd say I'm not sure how to lower them and as michka said you may be OK letting them lower naturally.