ok i have been looking into the Calcium reactors and it has pretty much almost come to a final decision between the AquaC RX-1, and GEO, but debating on the models (between the 618/624/818).....which one do u guys recommend, any suggestions are appreciated.

AquaC..
.http://www.saltysupply.com/AquaC-RX-...ns-p/acrx1.htm

GEO REACTORS....
http://www.saltycritter.com/calcium-...m-reactors.htm


could i use these as my ph probe for the calcium reactors
http://www.marinedepot.com/ps_ViewIt...t=DA1117&tab=1