maintaining ph levels with a calcium reactor

[pool_dude]

im contemplating on getting a calcium reactor, and looking to understand how to maintain the ph levels. how do you guys keep the ph level constant?

Some details about my tank if it helps:
29 gallon SW
1 cpr hob refugium
20 gallon tank filled with live rock for more bio filtration and for increase bio load.

[greenmaji]

The PH levels in the tank or the PH levels in the reactor? You use CO2 to lower the PH in the reactor.. just wondering if I understood the question thats all..

[pool_dude]

sorry about that, it would be the ph levels in the reactor. from what i know, the reactor needs 6.+ ph and that calc reactors need to be set up with CO2.

[greenmaji]

It souldnt be a problem with presurized CO2.. just turn the valve untill you get the desired PH.. Im guessing you could use a PH controller but that would be an extra 80 bucks at best..