What to do to ready QT between fish?

[Barrier Grief]

So, I recently (and successfully - thanks for the help RC ) moved a pair of Oscellaris from QT to DT. First fish in DT! Observed them for about 7 weeks in QT, and treated proactively with 2 back to back Prazi treatments just prior to going to DT. No copper used at all - on purpose. Fish are healthy - never observed any sign of disease throughout to this day.

What is recommended to prep QT for next inhabitants? Fish, as far as I know, are healthy - so part of me says just do a 50% WC to purge Prazi/siphon out any gunk, and then it's ready to go; but part of me says to drain/clean/start over, etc..., though doesn't seem I should need to or want to so I don't disturb biological filter. I tossed a sponge in DT sump a week ago, to prep for QT needs down the road, but doubt its bacteria population is large enough to be effective yet in my QT HOB filter.

I imagine responses would be different if disease was known to be in the tank, but given the circumstances, any advice on how to proceed?

 

[b0bab0ey]

I would probably drain the tank, start over. Clean out the HOB filter and everything. Just don't clean the sponge itself. Leave it sitting in s/w while you're doing all this. Or if you aren't planning on buying any fish for 3 more weeks just use the one in the sump.

 

[MuffsAbby]

I'm a relative newbie to SW, having QT'd 5 fish so far (2 clowns, then 2 chromis, then a flame...so only 3 QT processes, since some fish were QT'd together). Each time I have been in the same situation as you...no disease. Each time, I did a 30% WC, although I also wiped down all glass and cleaned all equipment (heater, filter housing, etc.).

That said, the bacteria isn't in the water. So, if you prefer to drain/clean/etc., then you won't disturb your biological filter as long as you keep your filter medium soaking in SW, as suggested by b0bab0ey. You should also start the tank up again right away and ghost feed the tank until your next fish go in.

 

[MrTuskfish]

This is a copy of something I've posted a zillion times. I think its the direction you're going anyhow. If your DT is known to be disease free; you can use DT to make WCs in your QT. My QT sometimes just sits for long periods with nothing but an HOB (with a sponge and used Chemi-Pure) filter to keep water circulating. I don't ghost feed or worry about a bio-filter in my QT until its needed. After QT use, I do siphon out crud. I've used this method for many years and consider it close to foolproof. I can never remember doing an ammonia-reflated WC in my QT.
"In regards to Qt cycling; I've done this for years. Get a HOB filter; I really like Aqua-Clear, they have a big sponge and last forever. Don't use the carbon or ceramic noodles that come with the filter. Also, have some extra sponges on hand, they're cheap. Keep a sponge in the flow somewhere in your DT. When you need a QT or HT, just use the sponge that has been in your main system in your QT filter---the QT will be instantly cycled. When done, toss the sponge and keep a new one ready in your main system.
BTW, Cupramine copper, used in a QT,will not destroy a bio-filter."