Nilson/Kalk Reactor

[Samw]

OK, its time to buy or build myself a Nilson reactor. The kalk dispensor for the Tunze Osmolator is just not good value for the money. For less than $130-$150, I should be able to build or buy a kalk reactor right?

I'm looking at this design. Any other good websites or better design? Can I get all parts from Home Depot? Is there a better place for parts?

http://mars.reefkeepers.net/USHomePage/USArticles/VisioImage/VisioImage.html

In this diagram, what's that horizontal line 17 cm from the bottom? I'm guessing its just a reference point for the center of the PVC.

http://mars.reefkeepers.net/USHomePage/USArticles/VisioImage/PlanVisioCalcSB.GIF

If someone alreay has one and selling cheap, I may buy it rather than build my own.