Did you have a look at the first article I posted? BTW Lime, pickling lime, kalkwasser, kalk, and calcium hydroxide are all different names for the same thing. This is what is in the article:
"* What Is Lime?
* Where To Get Lime
* Purity Of Commercial Lime
* What Is Limewater?
* How To Dose Limewater
* Vinegar And Limewater To Reduce pH
* Vinegar And Limewater To Boost Limewater Potency
* What Else Is In Limewater Besides Calcium And Alkalinity? Metallic Impurities
* What Else Is In Limewater Besides Calcium And Hydroxide? Mg++ and Sr++
* What Gets Left Behind On The Bottom Of The Limewater Container?
* Does Limewater Degrade Over Time? The Degradation Reaction
* What Else Does Limewater Do In An Aquarium? Raise pH Whether You Want It To Or Not
* What Else Does Limewater Do In An Aquarium? Raise pH When You Need It
* What Else Does Limewater Do In An Aquarium? Reduce Magnesium
* What Else Does Limewater Do In An Aquarium? Reduce Phosphate
* Limitations To Limewater: Limits To The Addition Of Calcium And Alkalinity
* Dosing Other Additives in Limewater
* Lime Safety
* Summary"
http://reefkeeping.com/issues/2005-01/rhf/index.php