Dosing Mg

[Madreefer]

A cheap easy alternative is
50lb bag of Easy Start brand icemelter for your driveway $40
4kg jug of Epsom Salts $5
Mix it 11-1
I use 1/2cup per 5gallons of freshwater in my top up resevoir.
Been using this for a couple of years now. You can't really argue that it's unsafe for reef tanks as I learned this from whatcaneydo and well, look at pics of his tank