High humidity problem

Hello every one! I currently have a 4' by 8' tent with a 1000 watt hps in it and I am having trouble keeping the humidity down. I'm looking for ways to lower the rh without using a dehumidifier or a lot of power usage. Right now inside the temp it stays around 72-75 degrees with the lights on and the rh is 70-80%!!!. The ambient temp in the room where the tent is placed, usually stays around 65-73. I have an inline sucking the air from outside the tent through the light and then out through the window. Any and all help is welcomed please and thank you!!

Is the area where the tent is very humid?

If not increase circulation if it is, your only option is a dehumidifier or you could try a ghetto way I saw on these forums. A big piece of charcoal.

Damp X or something like that you can buy at the store

The area where the tent is humidity stays around 40-50%. I was thinking of putting another inline fan in the tent but blowing air from out side the tent, into the tent. Hopefully that might help a little bit plus increase the circulation. Thanks Ill check out that damp X, I was reading about baking soda also if damp x is product similar to baking soda.