Originally Posted by Kushgodrex
When introducing a new filter to an established tank, how long until it can be used on another tank?
That would depend on the number of fish in the new tank. If you had just a few small fish in the new tank, the new media from the established tank could safely be moved to a new tank. You'd still need to monitor the water in the new tank to make sure the media was doing its job.
It would be better to move half the old media from the established tank and put that into the new tank. You'd just need to replace what you took from the established tank. Good bacteria makes a home on anything inside the tank that has a surface. Like, decorations, driftwood, lava rock, gravel and plants too. Bacteria will reproduce to its former level in the established tank in a matter of hours.