IMHO you're trying to do over think the QT tank. Honestly you can use a 10 gallon tank, an airstone, and a powerhead and have yourself a good QT tank. Like mr X said don't put rock, sand in there as they will tend to hold medications used to treat specific diseases and release them over time. The ideal thing as well is that most medications need to be cleaned out every day / every other day anyway.
I would also set up an additional tank if you want to raise fry and frag corals. This tank could also be plumbed directly to your main display to help with keeping everything stable.
This might or might not help you out but I'd look a bit more in depth at other solutions found on the forums and past projects people have done.
I would also set up an additional tank if you want to raise fry and frag corals. This tank could also be plumbed directly to your main display to help with keeping everything stable.
This might or might not help you out but I'd look a bit more in depth at other solutions found on the forums and past projects people have done.