No; the kalk settles on the bottom where the water input is. Fresh water mixes with the kalk, and is pushed to the very top where the outlet is.
This design should be the same for both stirrers and pump based kalk reactors.
And re: your tank; sounds good.. i was worried
.. take your time with the hardware.. i didnt, and ended up having to re-invent my tank several times over.
...and yeah, i LOVE the quality of the pieces i got from Divers Den. If i were buying lots of corals again, I'd strictly go through them.