Aquamist HFS-3 and MINI Tank GB

[killerfox]

You will need to run the tap in and out several times and check if the adapter will thread in. Take your time, first go about 3/4 of the tap then go about 1 turn more each time you run in the tap until you can get the adapter to thread in. The plastic kinda stretches while tapping it so that is why you have to run in the tap several times and check if the adapter will go in.