I am curious as to why you dont have live rock in your QT tank? the rock can filter the water when the nem expel those ammonia. the 24hrs cycle can produce alot of ammonia in the tank and that could also harm the nem during treatment. also to change the water i use main tank water to change out the water in the QT tank and replace the main tnak water with freshly made water and repeat the same process for 7-10 days however i see fit.