Dinky wrote:

SImplest way to keep a qtank, leave a sponge finlter running in an
established tank to trnsfer when needed. No substrate, a qtank isn't for
looks, mine is out of sight, anyway. I keep mine empty, and fill it from the
larger tanks when needed. Anything you put in the tank, including the sand,
will have to be sterilized after the tank is used. Sand sounds like a PITA
to sterilize. g

Two notes:

If the fish pass quarrrantine OK, which for me is 4-8 weeks, then I don't
sterilize the tank.

If the fish fail quarantine, everything in the tank goes in the trash. Total
cost: way less than the medication and heartbreak of dealing with an outbreak of
whatever in the fish room. This also means that the Qtank has very little in it:
a few handfuls of sand, a sponge filter, some surplus Java moss.