I'm not a big fan of DIY because anything and everything I've evern DIYed turned into junk. But if you wanna give it a try here's some links ... I know you're at a way different level of craftsmanship than I am.
http://jjgeisler.com/reeftank/diy_kalkwasser_reactor.htm
http://www.mv.com/users/besposito/nilsen.html
http://jjgeisler.com/reeftank/diy_kalkwasser_reactor.htm
http://www.mv.com/users/besposito/nilsen.html