Up and down pH
I run my CO2 on a timer with my lights it is on for 10hrs a day. I have noticed that it starts off in the morning at 6.9 after the CO2 has been on for 5 to 6hrs
the CO2 is 6.4 and goes back up to 6.9 by the morning when the CO2 is off. Is this too much of a fluctuation?