Thank you randy. Look like high PH is not surprising given the tank in the garage..i see the same trend on yours as well..pH will be high after lights are on peak for a while if you have a good amount of coral in there. No co2 being pumped out by you and your family, garage usually isn't air tight and corals should be producing a good amount of O2 during the day.
Here's one garage tank (~140 gallons total volume) with a ton of corals and 9-10 medium/large sized fish. Note that the respiration from corals and fish tank the pH at night. Even with a 20 gallon external fuge with chaeto, it's not enough to balance out the co2 generated by respiration of coral and fish.
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Another garage tank (~70gallons total volume) that only has nems and 6 small fish.this tank is still at 8.4+ at midnight. Plus there's a fuge with chaeto on this tank.
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