SPS dominated tank and PH

[ricwilli]

When you have a dominated SPS tank (150 gallon and above) and you use a CA Reactor, how do you maintain the PH from going down? Would a Kalk reactor be enough for a system that large?

[bertoni]

What's the pH now? Usually, low pH means that the ambient air has too much carbon dioxide in it. Fresher air can help a lot, if that's convenient. Otherwise, dosing kalk is a fine choice. This article goes into details:

http://reefkeeping.com/issues/2004-09/rhf/index.htm