I can’t speak on a Dastaco reactor. But I can speak on my observations with my custom calcium reactor that I built.
It stands 2 feet tall, the chamber is 8” diameter, and holds about 40lbs of media when full.
When I set it up I filled it a little more then half way and 25lbs of media. I run my effluent at a beaded stream. Meaning when the effluent comes out it streams for about 2 inches then starts to bead into drops. My tank is 90% sps so I have a high compression rate. The tank can eat a full dKh point in one day. My calcium reactor is so over sized for my system that I only have to run my pH in the reactor at 7.0-6.9 to keep up with the demand.
Calcium reactor