dosing question

You can use any food grade pickeling lime for a kalk substitue.
Epson Salt for Magniesium.
There are some other better home made additives then these.  You can find them on Reef central which will give you instructions on how to make the correct version for you.

 

here is how you make the stuff cyber was talking about. http://reefkeeping.com/issues/2006-02/rhf/index.php#15
Another option would be get the stuff from Bulk Reef Supplie. I don't know if it is higher grade, but it works. That is what I use.

 

I use Mrs Wages pickling lime, wal mart has it. works good for me.

 

Good suggestions. I also use this handy calculator to determine how much of what to dose. Its relatively foolproof.
http://reef.diesyst.com/flashcalc/flashcalc.html