Here's the Kalk
setup. The back bucket uses a toilet float to control the water flow. I keep a 1/2 pound or so of Calcium hydroxide in the bottom and refresh it once a month or when I notice it's used up. When the water level drops enough the valve opens and pressurized water enters and stirs up the Calcium hydroxide.
The two buckets are connected using airline tubing. The second bucket (in front) is used to catch any precipitate caused by impurities in the water or in the Calcium hydroxide. This bucket is completely full and sealed. The bucket connects to the sump through the side via more airline tubing and into the styrofoam block.
As the water level in the sump falls the limewater drips into the sump. There is no siphon, it's all gravity fed.
The second use for the styrofoam is if the water level in the sump gets too high it will not backflow into my limewater and ruin it. I require this feature because I have a pair of 32 gallon surge devices on my lagoon that sometimes both go off at the same time adding about 50 gallons to the system within a few seconds.