[DJ88]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr> FWIW, changes in CO2 only will have no impact on alkalinity (but of course huge ones on pH). So if you bubble CO2 into seawater, the alkalinity will remain unchanged (but the pH will drop). Likewise, if you somehow suck off all the CO2, the alkalinity will remain unchanged (but the pH will rise) Changes in alkalinity through the day would, IMO, reflect process involved in alkalinity addition (limewater etc.) and alkalinity consumption (e.g., calcification, parts of the nitrogen cycle, etc.).
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That is a quote from Reef Central discussing alkalinity levels and CO2.

You may want to look at your CA reactor. I don't think it is doing what you think it is. FWIW