High humidity in new grow tent

Hello folks! I just got back into growing took a few years off due to children but we’re back up and running. With my current setup my RH is around 75-91 humidity in my room ( currently in veg ), but I need to figure out how to get it lower. I’ve ran this same setup before but all of a sudden my RH is crazy high.

here’s my setup

4x4 tent ( 15 plants 1 month veg )
Portable ac hooked up to 2 400 watt cool tubes.
6” inline fan 440 cfm pulling the ac air through the cool tubes exhausting into the bedroom
1 9” Oscillating fan 1 4” oscillating fan blowing in the room.

currently have no exchange of fresh air. I do have another 4” inline fan. I don’t know if I should push fresh air in? Or pull air out with it?

my room temps are perfect 71-79 degrees. I’m finding my 6” ducting is sweating from the ac running through it. I was using metal ducting ( sweating really bad ) switched to plastic flex duct got a little better.

I put two damp rids in which barley helped at all. I have a 10x10 tent on the way and 3 600 cool tubes. Would like to get this under control before I move to the bigger room. I’m looking at dehumidifier but I’m hearing that raises the tents overall ambient temp a lot. Any other advice would be great.

can get pics if need be of setup.

tldr; room temp perfect 71-79 overall RH ridiculously high 75-91 need to fix

AC will act as a humidifier. I assume you mean your tent is 4 meters by 4 meters? If your going to run AC you need it to blow into the bottom of your tent with & have an exhaust pulling out from the top of the tent. Dont push your AC through the cool tubes have a separate fan for them if you need to run them