Humidity problem in small grow room

I have a 5 by 7 room that's 6.25 feet tall.
I have 2 600 watt lights but I'm only using one since half my plants were males.
So there's 4 plants in 2 gallon containers so they're medium sized plants (2-3 feet tall).

My humidity has been 50-70% the last week or so. I don't know how to get it down. Temps are around 65-72 degrees. I don't want to use a dehumidifier since it's a small room and the heat from the dehumidifier will make the room too warm. Also they use alot of energy (usually 400-800 watts). I have a 6" fan that's rated 400 cfm sucking air through a filter past the lights and out the room. I have my fan and a small 50 watt mini dehumidifier plugged in to an atmosphere control device.

The only thing I can think of is getting a higher rated cfm fan (how much more than 400 cfm)? Or just add an inline fan? Does this humidity seem high for such a small room, such few plants, with what I thought was a high enough rate fan? I was told a 400 cfm in a 35 square foot room cooling 2 600 watt lights would be plenty. Was this wrong?

In order to properly control Humidity you're gonna need a Dehumidifier, unless the source for your fresh air is stable all year round. Anything above 60% in flowering can cause disease issues. I'd look at smaller dehumidifiers that don't run at 600 Watts. I have a 70L Dehumidifier and it runs at 800Watt 6 amps, so you should be able to find something alot smaller to help with that room and not raising temps too much.

Alright. So getting a higher cfm fan won't completely do the trick then, huh.
If that's the case, does anyone else use a good dehumidifier that doesn't blow too much heat? Lower wattage prefered but the heat would be the most important.
Thanks for the input marantz.

Will using an air conditioner lower humidity and cool the air? Should I just buy a portable a/c unit instead of a dehumidifier?

They do take the humidity out of the air, but you would be cooling at the same time, so that's something to think about.

True but I don't think I'll have a problem having my growroom too cold in the summer. I'm at 73 degrees with one 600 watt so I'll assume with both 600's i'll be close to 80. I just don't want to dole out 200 bucks and then realize the room's too warm in a few months (when it's summertime) and now have to buy a 2nd $200 appliance. If the a/c lowers humidity just a little and not as well as a dehumidifier then I guess it won't matter.