But are you doing anything to evacuate the hot air from the tent? The dehumidifier needs to suck in the moist air from inside the tent, remove moisture and then blow it back in. If the intake for the dehumidifier is outside your tent, it is basically doing nothing but adding XX% RH air to the tent.
The way my tents are set up is to have an intake fan draw air in from an external carbon filter ( i have cats so i want my air filtered) and then a seperate fan sucks the hot air from the tent through my HID light hood and oit of the tent through another carbon filter. I have a dehumidifier inside my tent so regardless of how the air changes, the dehumidifier keeps the rh constant. I also have a portable ac so later when it gets hotter, the portable ac goes in the tent and the hot air exhaust ducting patches into my evac fan. Once you get it adjusted it works like a symphony, each piece doing its part to make something freaking magical.. your humidity could also be affected by having the res in the tent, is it covered? At any rate its not that big of an issue considering your target RH for veg should be between 50% - 70% (i prefer the lower end) but for flower youre going to want to get that humidity down to around 40-50%, thats when you really need to monitor it