Yes, once uronema is in a system, it's there to stay unless drastic cleaning is performed.
If run the system just like regular with skimmer, filters, pumps and poweheads running... then add a could cups of bleach to it. Then run let it run a few days. I use enough bleach to where i smell it standing near the tank. This is how i clean my quarantine tanks.
An added measure, i then soak the equipment in a 50/50 vinegar solution and then scrub each piece of equipment with brushes... then air dry a few days.
Good luck...
Ps... as a safe measure, i'd toss the sand.
If run the system just like regular with skimmer, filters, pumps and poweheads running... then add a could cups of bleach to it. Then run let it run a few days. I use enough bleach to where i smell it standing near the tank. This is how i clean my quarantine tanks.
An added measure, i then soak the equipment in a 50/50 vinegar solution and then scrub each piece of equipment with brushes... then air dry a few days.
Good luck...
Ps... as a safe measure, i'd toss the sand.