How many fish in your 29 would be in jeapardy if you put them into the dt? If your current fish are way more important to you than your new fish, then I would make a batch of ten gallons of new saltwater right away in the qt and then put your new fish in there. Or maybe it's better to make 5 gallons and mix the nitrite water with freshly made? I don't know. Depends on how much nitrite you got in there.