How important is magnesium?

[Jl330]

I've been dosing kalk and have an algae scrubber. Alk and calcium have been stable for months and haven't done a water change. I haven't thought about magnesium, haven't even tested, but is it super important and should I be dosing it? I guess testing would be step 1 here.

 

[Hemmdog]

I've been dosing kalk and have an algae scrubber. Alk and calcium have been stable for months and haven't done a water change. I haven't thought about magnesium, haven't even tested, but is it super important and should I be dosing it? I guess testing would be step 1 here.

It is extremely important. Alk and calcium don’t work properly without the correct amount of mag.

 

[wutang]

Agreed. Alk, calcium and Magnesium are all very important for a healthy reef tank with corals and fishes.

 

[Jl330]

I think my test is flawed or my tank isn't using any mag

 

[SPR1968]

As already said magnesium is vital for the water chemistry to work correctly but it tends not to be used up as much as alkalinity and calcium so you may not need to dose it. I rarely need to add any in a full mixed reef.

 

[Dr. Reef Verified Sponsor]

mag acts like a referee between alk and cal, without it both go wack. Mag has a large window of acceptance, as long as its within range you are good. As low as 800 to as high as 2100. most people keep it around 1300-1500 range