Epson salts as magnesium?

[plancton]

Is it a good idea to use epson salts as magnesium?, I heard they were cheaper. Any pros and cons?, do they contain phosphates or other stuff I should be worried about?.

What´s the recommended dosage of these epson salts?.

I´m going to check prices at the pharmacy.

 

[dzeadow]

stuff's wicked cheap and works. I guess you're not supposed to use it too often as a mag source though because it does contain sulfer (magnesium sulfate or something). But is fine for the occassional addition. It's in Randy's recipe

http://reefkeeping.com/issues/2006-02/rhf/index.php

 

[MrRyanT]

For the most part my mag is maintained by the salt I use, but if and when I need to add some then epsom salt is what I use. Never had any problems with it but don't use it very often.