Welcome to TRT Jared (an our other new poster, Unleashed!)
I saw your numbers, and the low pH of your system is allowing you to keep your calcium and alk at the levels you posted, so I don't doubt that the numbers are a true reflection of your values. pH in marine aquaria is primariy a reflection of the
CO2 content of the water column, and to some extent the alkalinity (not a very big part though, although it may reflect where your pH will go as the alk content buffers the water column. High alkalinity tends to drive pH to 8.2 or so depending on
CO2 content in the water column (however, the immediate effect will most likely be a drive u in p, followed by a gradual decline back to 8.2 as the alkalinity dissociates into its constituents and whatever results in equiibria of the different crbonate species are demonstrated in the tank (ie., carbonate may precipitate Calcium as it is formed from bicarbonate (and bicarbonate may aldo precipitate high levels of calcium, but it is more soluble than the carbonate species of this reaction), resulting in a gradual drop in both ca and akalinity as equilibrium is attained for the suersaturation quotient for that articular set of conditions.). If your pH stays at 8.0, and there is no issue with your probe or meter, then high CO2 is most likely the cause.
Do you have a Ca reactor? excess CO2 adjustment will result in high C2 and moderately high Alkalinity, but pH in the range youre experiencing.
this requires an adjustment in your delivery rate for the
cO2 to the reactor, a simple but sometimes tedious task.
Is your house air conditioned and kept closed all summer? Is the aquarium located in an area with a large number of people (dormitory or classroom, for example, or where you work if there is an office environment)? In the winter, use of gas logs, gas furnaces, or all year round with a gas stove and/or oven may drive up your indoor environment's pCO2, and as seawater is at almost instantaneous equilibrium with the atmosphere in the presence of good surface area with turbuance, will consequentoly drive up pCO2 of your ASW in the tank, driving down pH.
Systems with glass covers, tight hoods and stands, covered sumps, inadequate circulation, or deep tanks with a relativey small surface area in relationship to total volume are apt to have these same conditions arise. Sometimes the rest of the house will be fine, but location in a seldom used room or a basement may allow
CO2 to accumulate as well. Systems with large populations of fishes may experience these same conditions, but this is most often remedied with good circulation without too much trouble.
Think of conditions that might contribute to either excess CO2 roduction, poor exchange of CO2, or conditions that allow for accumulation of CO2 as probable causes for your current issue.
HTH, and again,
Welcome to TRT.
