Quarantine Tank Help

[daplatapus]

Congrats on the upgrade.
My first question would be how often did you do water changes? Is there any type of filtration on the QT? One of the big killers in a QT will be your Ammonia. The more fish in the QT the faster your ammonia will climb. Having a filter system that's got the bacteria you need to process that ammonia is the key. Or using something like Amquel to treat it.

[gregzz4]

My QT is a bit overboard for equipment

20g QT has;
ATO
RKL w/SL1 and pH probe
100w Eheim
Aquaclear 50 with surface skimmer attachment
Quiet One 1200 w/8w HOB UV ( UV turned off for first week or so )
Ammo Alert
Air pump and stone ( back up in case pH dips below 7.8 )
15w T8
Eggcrate
Computer fan on the eggcrate, and controlled by the RKL

Chems;
Stability
Am Guard ( just in case )

Brad's great suggestion of putting the AC foams in my sump to seed bacteria was probably the biggest reason for my QT success
The foams were in the sump for probably 2 months in the first chamber, before my socks

The QT water level is about 1/4" below the trim so the filter and HOB sterilizer splash return water for aeration

I fill the QT with new water, but have used DT water in the past
When the new fish are coming home, I put the foams in the AC
Once the fish are in, I start using Stability as per instructions
I monitor ammonia, both with the ammo badge and a test kit. If I see any high ammonia, I dose Am Guard and continue monitoring

Once I'm past the initial Nitrate cycle, I turn on the UV, keep monitoring params, and usually do a weekly 50% WC. I rinse the foams in the old water and swap them top to bottom

My pH was never low enough to worry about, even during Hypo, so I've never had to use the air pump yet

The WCs are done with new water until I'm ready to transfer the fish, then I use DT water for a change or two to ease acclimation

[jostafew]

I also have a 20gal QT tank which held a Kole tang for a month before going into DT. In fact its condition improved during its stay in there. I have a very basic setup, PVC for the fish to hide in, heater, Bio-Wheel filter, small Koralia powerhead, CF light fixture. Same routine as you, take about 5 gal out of the DT and use it for water changes in the QT, done every week or so while there is livestock in there (less frequent when it's sitting dorment). During extended periods without livestock I just shut the QT down and move the filter over to the sump on the DT so it can maintain its bacterial population.

I think daplatapus hit it on the head, too big a bio-load too quick. I probably wouldn't have tried to QT all three of those fish at the same time in such a small tank, even with the good water change schedule. Sorry to hear that you lost those two tangs.


P.S. if anyone is looking at my signature and wondering if there is a Kole tang in a 35gal tank, rest easy as that was in a previous (larger) tank.