Iterate OD calibration when refreshing the media

Hi guys!

I’m planning to run a turbidostat which is going to be a long period (for weeks).

I am wandering that when the prepared media is fully used and refresh the media to the one of same ingredients, should I recalibrate the optical density?

During my several uses in the past, I observe that the OD change sharply when exchanging the media (which I tried to make them all identical…).

My concern is that if I recalibrate during the run, the OD changes during that time…

Do you have any thoughts?

Thanks you in advance!