# Best way to dose Ca/Mg?



## abnormalsanon (Jun 6, 2006)

I'm about to make a purchase from Greg Watson and would like to know how folks dose Ca/Mg. A while back I ordered calcium carbonate, only to find out that it's no good in terms of the Ca/Mg ratio. So what do you use? And please use both the full name and abbreviation for this chemistry-impaired person


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## aquasox (Sep 11, 2005)

Magnesium sulphate (MgSO4). You can also order that from Greg Watson.


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## abnormalsanon (Jun 6, 2006)

Aquasox, is that in addition to the calcium carbonate, or instead of? Thanks!


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## hoppycalif (Apr 7, 2005)

Why not just buy GH Booster, PMDD Store: Barr's GH Booster, Dry Aquatic Fertilizers, which will dose a good ratio of magnesium and calcium, as well as a few other minerals.


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## abnormalsanon (Jun 6, 2006)

Thanks Hoppy, it was already in my cart but I just wanted to check here before I submitted my order. After I bought the wrong thing last time I figured I'd save myself the money/grief. Thanks


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## Salt (Apr 5, 2005)

Greg Watson's "calcium carbonate" is actually dolomite, which is already a combined calcium/magnesium source.

I use pure calcium carbonate to remineralize RO water. By doing a test I have determined that I have enough magnesium. It is coming into the tank by way of the Seachem products I dose and the fish food.

Once the information was revealed that magnesium levels greater than 10 ppm will stop some plants from growing, I've done away with "ratios," and just aim for a magnesium level of 5 ppm (20 ppm as CaCO3 on a test kit).

If you're refering to the fact that dolomite doesn't allow one to target their own "ratio," that's correct. Otherwise, pure calcium carbonate is perfectly fine in terms of allowing a user to control calcium and magnesium ratios separately.


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## aquasox (Sep 11, 2005)

Its in addition to the CaCO3 that you are adding...but it seems you've got the gH booster already.


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## MatPat (Mar 22, 2004)

If you take a look at the  Perpetual Preservation System Link , and then select the Water Hardness, Magnesium and Calcium, you can see Edward uses Calcium Sulphate, Calcium Chloride, and Magnesium Suplhate for increasing Ca and Mg levels.


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## werner (Jul 6, 2006)

> Once the information was revealed that magnesium levels greater than 10 ppm will stop some plants from growing...


Can you give more information/links for this? I'm having problems with this and can't seem to find anything definitive.


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## MatPat (Mar 22, 2004)

I think Edward and Salt are the two who have done most of the testing/research on Mg levels. I do believe a search on magnesium and/or Rotala wallichii will give you the answers you are looking for 

Here is a link to get you started: http://www.aquaticplantcentral.com/...zing/9519-calcium-magnesium-relationship.html


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## Salt (Apr 5, 2005)

werner said:


> Can you give more information/links for this? I'm having problems with this and can't seem to find anything definitive.


See the link above, specifically,

http://www.aquaticplantcentral.com/forumapc/showpost.php?p=69306&postcount=22


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