# Water very hard - do I add Ca and Mg



## mark77ap (Jan 6, 2008)

Hi,

I have been doseing EI for about 1 year now. I seem to constantly be battling algae of some sort. I figured I would try this PPS-PRO. It sounds much easier and I like the idea of not having excess nutrients in the water.

With EI, I never dosed Magnesium or Calcium. My Tap water is 22 dGH and 11 dKH. Should I sill add the Ca and Mg to the formula for PPS-PRO? Will it raise my hardness. I have to pump in loads of co2 as it is 

Thanks

Mark


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## hoppycalif (Apr 7, 2005)

If you use a municipal water company tap water you can get a copy of their water quality report, which usually lists both the calcium and magnesium in the water - almost always a range of values that may be found. If that shows you have some magnesium, around 1/4 of the ppm of the Calcium more or less, I don't see where you need either calcium or magnesium. But, if the report shows little or no magnesium then adding it is a good idea.


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## mark77ap (Jan 6, 2008)

hoppycalif said:


> If you use a municipal water company tap water you can get a copy of their water quality report, which usually lists both the calcium and magnesium in the water - almost always a range of values that may be found. If that shows you have some magnesium, around 1/4 of the ppm of the Calcium more or less, I don't see where you need either calcium or magnesium. But, if the report shows little or no magnesium then adding it is a good idea.


Thanks. I do have a copy of the report but it only states the hardeness as 328 mg/L (23 grains). It does not sepcify Calcium or Magnesium individually.


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## hoppycalif (Apr 7, 2005)

With water that hard I find it difficult to believe you could be short of magnesium. But, others (Edward?) may differ.


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## ray-the-pilot (May 14, 2008)

Municipal water suppliers are not required to report water hardness; although many do as a curtesy to their customers. 

It is impossible to know the ratio of Ca/Mg from the total hardness; however, with such hard water there is probably enough Mg. 

If your not strapped for cash you can get a total/Ca/Mg hardness test kit from LaMotte. It’s like $60 with shipping. 
If you can do chemistry you can modify the Red Sea salt water Ca kit to test fresh water by using a larger sample (50 – 200 ml). I could not get the Red Sea kit Mg kit to work on Fresh water.


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## Bert H (Mar 2, 2004)

Do not assume a high gh indicates you have enough or the proper ratio of Ca/Mg. If the water source is from a limestone aquifer, chances are you will have tons of Ca, and little Mg. I have well water, gh12-13, from a limestone aquifer, and I add Mg to all my tanks. If I don't I get lots more stunted growth on certain stem plants.


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## hoppycalif (Apr 7, 2005)

Bert, that's a good point. I grew up in Missouri, where the "limestone" is actually a mix of calcium and magnesium based rocks, so the water had both. But, I understand that Florida is largely a pure limestone state.


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