[Raymond S.]

If this is a Ph swing from injected CO2, then it's not a problem as they happen for different reasons. Don't remember the deails of it but did ask this question about a month ago on here as I've seen most who use injected CO2 say they drop Ph from in the 7's to low 6's each day and I asked why some people say it's very bad on fish etc to swing the Ph up and down but those same people sometimes have injected CO2 and say it goes from the 7's to the 6's each day.
The reply was something to do/w mineral content not being effected in the one that is caused by CO2 injection.