Interesting thing about shutting down biofiltration and cranking it up again: a PHD down the road that produces hybrid striped bass, said one year he shut down some of his rbc's
and when he cranked them back up he had a hell of a time with morbidity and mortalities. Said he finally realized the heterothrophs had taken up shop in his filters and were outcompeting his autothrophs due to the shutdown stagnant anoxic enviroment that favored the heterothrophs. Since they multiply much more rapidly than the autotrophs he had issues. He told me if I ever shut down a biofilter it's better to sterilize it and start over.
Biofilters 101
You need to keep them working healthy, otherwise you'll run into trouble.
I'm surprised your PHD didn't pick up on this fundamental requirement.
Your filtration system is the primary Heartbeat.
