Then he still has Ich and always will. PBT's are Ich magnets and (or course) it is now present in your DT. Moving him to the DT now though would stress him again and that's when they go full blown outbreak often. Give it a bit more time before you put him back.
Self care is tank care.
Wellness of your tank depends on the five pillars of care - mental, emotional, physical, environmental, and spiritual.
I learned this from our Guru Erin on the last tank retreat.
The fact that it only tests for two parameters is missing the point. For many reefers, even if it only tested phosphate, it would be worth it. There was a time that was considered the holy grail in future thinking.