Magnesium - what when where why?

I have searched through the old threads and found tidbits about magnesium here and there.... can someone give us a run down on what magnesium does for the tank, how often to dose, How to dose it (slow dose ie: add it to your top off water and let it drip in slow, or dump it right in the sump in fast water?) What kinds of things in the tank deplete it that just doing your weekly water changes don't replenish it?

Thanks for the replies.

GLTA

 

Chemistry and the Aquarium

 

Chemistry and the Aquarium

It is a long article and somewhat advanced but it works for me.
It is under my favorites for saltwater links and chemistry.

Jim

 

Next time I'll type faster or check to see if you're online. lol

Jim

 

Gracias............ Good article.