Calcium reactor question

[Ryanerickson]

Update put the 2 reactors in line co2 only goes in the first reactor, co2 line on reactor 2 is plugged I use course arm media in reactor and run the ph pretty low reactor one ph 6.2 reactor 2 is at ph 6.4 this is working great tank is holding at 8.1 kh and 400ppm still can not get it to stay above 420 but don't mind manually dosing calcium chloride for that.