help with cheap mg and pickling lime.

[seagirl]

I currently use seachem reef kalkwasser to maintain my ca and alk. I want to switch to something cheaper. Will the calcium hydroxide from two part solution.com be the same thing? Will i need to change the ratio of kalk i add to the top off water? Here's the link-

http://www.bulkreefsupply.com/Calciu...1_3/index.html

I also need a cheaper mg supplement, the Tech-M is killing my reef budget. I was looking at the same site and they have mag. chloride flakes and mag sulfate. Can someone please explain to me how i can use these to replace my Tech-m supplementation? Thanks.