A kalk reactor or better yet a still reservoir for dosing self purifying kalk is simpler, cheaper ,more consitent,with some advantages for purity,dosing consistency and increased ph,ime. All you need is a container( bucket,trash can, whatever with a lid) ,a perstaltic pump with a timer or a gravity drip . My calium reactor,two pumps, regualtor, CO2 bottle has been on the shelf for over 5 years now.