Left town, ORP down, PH up

[RussC]

okay, this has been one of those moments I think every reefer has. I’m out of town. This is the longest I (and family) have been away from the tank. My ORP has slowly declined and PH has slowly increased. It’s interesting to me. You can tell right when we left. Why is this happening?

 

[chipmunkofdoom2]

I cannot speak to the relationship between pH and ORP. I can say that pH in seawater is determined almost entirely by CO2. Another factor that affects pH is carbonate alkalinity. If the carbonate alkalinity remains constant, the only other factor that influences pH is CO2.

If no people are in your home consuming oxygen and producing CO2, then the overall CO2 concentration in your home will trend down. As overall CO2 goes down around your tank, CO2 concentrations in the tank will also fall. The pH will rise as a result.

 

[RussC]

Very interesting. And it totally makes sense. My home is sealed up tight with insulation to begin with. So PH in my tank has been relatively low as a result.