A total of 1 review of this product on Reddit.
I had the same problem as you. 6″ exhaust sucking the humidity right out of my tent. Even with a AC Infinity my humidity was still super low in the mid 40s.
I added 1 cool mist humidifier, it got up to about 55%RH. Which is decent but wanted higher for the girls when they are young. Added another cool mist humidifier, and now I can get all the way up to 80% RH or a little higher if I ever wanted. I have 3 small fans in my tent as well. 2 stationary blowing on different parts of my light. The last one oscillates right above the canopy. As the oscillating one turns it blows the mist from the humidifier all around the tent. I plan to do a perpetual harvest type of staggering in my tent and having 2 of them lets me fine tune things more.
Also, I would make sure your humidifier has a humidistat on it. This is the one I have: https://www.amazon.com/dp/B009W7CSTS/ref=cm_sw_r_cp_apa_fabc_CAJ3Fb3RDC8W0?_encoding=UTF8&psc=1
This is also a good one: https://www.amazon.com/dp/B07H2717BM/ref=cm_sw_r_cp_apa_fabc_-AJ3FbMZ89XSR?_encoding=UTF8&psc=1