Relative humidity of 68% with lights off isn't so bad as I understand it. The main reason you want to keep humidity down is to avoid mould and mildew problems. So long as humidity drops well below 68% daily during lights-on (vents on) then you shouldn't have problems. Consistent relative humidity above 70% in a warm room is where you start to risk significant mould growth, though the danger point is lower in a colder room as it's not high relative humidity but high water vapour pressure that allows mould and mildew to grow. How cold does your room get during lights-off?
Supposedly a plant will produce more resin if it grows in dryer air, as the plant produces extra resin as a kind of 'chap stick' to help keep the moisture in in a dry climate. That said, there are plenty of growers living in humid climates that manage to produce good smoke with RH values regularly exceeding 80% - you just have to be very vigilant to ensure mould doesn't take hold. If you're worried a dehumidifier will suck moisture out of the air in your grow space and keep everything nice and safe.
if your running at 70 degrees and your dehumidifier has to run for lets say to drop the humidity aroung 25%, then your temp will raise to about 85 degrees or maybe more.i think i found a pretty good dehumidifier that im gonna use so i should be straight. im not to worried about the temperature tho because it stays in the mid to low 70s with the lights on so it shouldnt get to much warmer, thanks for all the good advice now i know rite where to keep my levels at now. ill be straight for the rest of my grow
Best bet for temp issues is get ahold of some dessicant and put it in cheesecloth type mesh bags, hang it around the plant site and that should help out with your humidity, combined with the dehumidifier! You can build a makeshift vent to exhaust the heat from the dehumidifier.damn alrite well ill get the dehumidifier in there an see how high the temp raises, maybe i can find a small dehumidifier or something that will make less heat