So I have a 4 x 8 tent with (3) 1000 W full spectrum LED lights. I only have one oscillating fan going through it and my humidity has spiked to 76%! My plants are in their 1st week of flower so I have to resolve this ASAP! I live in MI and we been having a lot of rain. Would a 20 pint dehumidifier help or should I buy more fans?
Circulating fans aren't going to do anything.
If you are running CO2, then you need a dehumidifier. If you aren't using CO2 then you need intake & exhaust fans to bring in fresh air. If the air you bringing in is still high in humidity, then you will also need a dehumidifier.
The size of dehumidifier is dependent on how many gallons of water you feed per day.
What lights are you using? Most LED's that are marketed as 1000w are usually only 100-300 actual watts. Very few LED's are 1000W.