Dosing magnesium

[reeftard31]

So I have a 21 gal tank and have never dosed mag before. I checked my levels and it’s appearing to show 450 ppm and that I need to add almost 2000 ml of EVS mag solution. I’m just wanting to make sure that sounds right or maybe I did the test wrong and there’s no way?

 

[TX_REEF]

Are you sure mag is the only deficient component? I know @Randy Holmes-Farley advocates to not dose or test mag individually as a deficiency of mag generally indicates a deficiency of other components that can be better handled with a broader dosing solution?

 

[gtguy256]

Check your salinity first. As mentioned above getting a Ca and ALK reading will help to determine how to correct any imbalance.

 

[Randy Holmes-Farley Verified Community Expert]

Magnesium is definitely not 450 ppm in any reef tank.

How did you measure it?

 

[reeftard31]

I used the Salifert test kit

 

[Randy Holmes-Farley Verified Community Expert]

It is likely you are reading it backwards, as often happens with Salifert.

Be sure that reading the table and syringe, if you dosed a full syringe to get to the color change endpoint, magnesium is high, not low.

A low level means you added very little from the syringe to get to the color change.