Can dosing MAG raise dKH?

[amazongb]

I’m not a chemist but the magnesium alters the calcium and alkalinity bond. It may be that your magnesium levels are not raising your alkalinity but keeping too much from bonding with calcium which could or could not raise your levels.

That was my initial thought, but if you compare my first test to me second test, both mag and alk are up..

 

[eea60123]

I was just thinking out loud, but that would be the case. You need a certain magnesium level to stop precipitation or the calcium and alkalinity bonding to a level where it would precipitate out or become useless to the corals because they can’t uptake it. As your magnesium levels increased to the point needed(1350 +/-) the calcium and alkalinity bond would alter to a natural level where they would not over bond together. It could be a million things, but I don’t see any glaring problems with your parameters that would cause me to freak out. I have a Red Sea test kit and I’m off on my testing due to light on a regular basis. I normally look at when I think it changes to when I know I went too far and go from there. It’s normally within .2 to .4 so I don’t worry about it.

 

[Randy Holmes-Farley Verified Community Expert]

I’m not a chemist but the magnesium alters the calcium and alkalinity bond. It may be that your magnesium levels are not raising your alkalinity but keeping too much from bonding with calcium which could or could not raise your levels.

No, that is not impacting this situation. Magnesium does not cause alk to rise by this or any other mechanism. You can reduce demand for alk by reducing precipitation, but it does not ever cause alk to rise if you are not dosing any alk.

 

[eea60123]

No, that is not impacting this situation. Magnesium does not cause alk to rise by this or any other mechanism. You can reduce demand for alk by reducing precipitation, but it does not ever cause alk to rise if you are not dosing any alk.

Thanks for the clarification.

 

[djreef]

magnesium dosing won’t impact pH or alk, unless you dose some strange chemical.

So, Randy - (long time no speak) is it possible that the test kit could be fooled by the bump in Mg and is simply misreading it.

I’m currently dosing Mg in a freshwater system for plants and noticed a bump in my DKH right after I dosed hydrated MgSO4 into the system.

Hope you’ve been well.

 

[Randy Holmes-Farley Verified Community Expert]

An alkalinity test should not be impacted by magnesium or sulfate, but there may be impurities in the product that boost alk.