Ok wow thanks for that link genetics

After reading about the Randy 2 part its pretty clear although some questions did come to mind and so if anyone can help me that would be great
1. He suggests u mix with a gallon of water..although he didnt mention it.... de-chlorinate the water first right? Then when he talks about mixing the magnesium he says to mix with purified freshwater?...does he mean like RO water?
====>I dont own a RO unit yet..iam gonna be new to coral keeping so iam starting out small
2. For the Magnesium recipe he says to mix with epsom salts?...sorry iam not familiar with these......can anyone please point me in the right direction?.....where to buy epsome salts?....what brand?
and thats about it....everything else was very clear to me..thanks guys