Kalk reactor,, how did I do?

Looks good, It probably would have been a good idea to put the output of the pump all the way at the bottom to keep the kalk from getting packed up down there, but overall it looks great.

I was going  to suggest a 45 elbow to help, it should be fine, thats really close to the same design as mine.  I would suggest only doing several cups of kalk at a time and refilling biweekly or so.  That will help from getting too much sludge at the bottom and help keep it in suspension.
I've noticed with mine that if I put in too much kalk I'll lose the pH raising effect over time even though there is still plenty of kalk in the reactor, and have gone to adding a cup or two a week to help out.
What size is your system, that looks like a pretty big reactor and should last you a while.
good job!

Be very careful with that size of a system, kalk can be pretty dangerous.  We run ours 24/7 through our RO, do you use a JBJ auto top off or what method do you use.
I have a safe guard in mine that my reefkeeper shuts off the topoff if my pH rises above 8.45, and i have about 600 gallons and evaporate about 15-20 gallons a day.  If you use a reservoir for top off I would make sure it holds only enough top off for one day at a time to be safe if you don't have another method of redundancy.  I would start off with probably only a half cup for that size system.  As long as the water looks pretty saturated when it stirs you should be alright.
How often are you planning on turning on the mixing pump?

I have a feed line from my topoff tank which I have put a tee in to feed reactor. The topoff tank holds 10 gal which I have to refill once per week. I have put a valve on the reactor feed to the sump to regulate the kalk drip. I thought this would be a safe method to use as evaporation wouldn't affect the kalk supplementation rate. Another question. Am I correct in my understanding that I should let the reactor sit for 24 hrs. after I first fill it and mix before I start to drip? I plan on putting the mixing pump on a timer to cycle on for fifteen minutes every 6 hrs., does that sound ok?