Magnesium

[finley]

I have some test kits at the moment that don’t include magnesium, however they do include carbonate hardness. I have been told to keep a torch coral is should aim to keep magnesium around 1300-1400, but due to me not haveing a specific test I was wondering if I got a good test of carbonate hardness would that mean my magnesium is good aswell ? SORRY IF I DONT MAKE SENSE

 

[KrisReef]

They are related in water chemistry but different ions that interact and it would be easier to get an answer with a test kit instead of asking a hypothetical here.

But, if you are using salt mixes with an ample amount of magnesium and you do frequent (say weekly) water changes then you can expect that your Magnesium levels will be fine if your Calcium and alkalinity levels are ok because they tend to deplete faster than Magnesium. Comes with assumptions but in theory it would be fine if the salt mix isn’t deficient in mg.

 

[Randy Holmes-Farley Verified Community Expert]

I have some test kits at the moment that don’t include magnesium, however they do include carbonate hardness. I have been told to keep a torch coral is should aim to keep magnesium around 1300-1400, but due to me not haveing a specific test I was wondering if I got a good test of carbonate hardness would that mean my magnesium is good aswell ? SORRY IF I DONT MAKE SENSE

No, that’s not a good conclusion.

A much better conclusion is that it is fine unless you have added a large amount of alkalinity for an extended period of time. If not, Mg will be close to what comes in your salt mix and will be fine.